Help seeking theory postulates that people follow a series of predictable steps to seek help for their inadequacies, it is a series of well-ordered and purposeful cognitive and behavioral steps, each leading to specific types of solutions.
Help seeking theory falls into two categories where some consider similarity in the process’ (e.g. Cepeda-Benito & Short, 1998) while others consider it as dependent upon the problem (e.g. Di Fabio & Bernaud, 2008). In general help seeking behaviors are dependent upon three categories, attitudes (beliefs and willingness) towards help-seeking, intention to seek help, and actual help-seeking behavior.
Do you ask for help when you need it or do you have the view, “I have to do it myself, no one can do it except me?” From a motivational perspective, help seeking is an adaptive cognitive strategy that indicates a striving for mastery and achievement (R. Ames, 1983; Karabenick, 1998; Newman, 1998) and a general problem-solving strategy (Nelson-Le Gall, 1985). If help seeking is an adaptive strategy, why do teachers observe that students
who are most in need of help are often the most reluctant to seek help? We have learned from research that seeking help from others can have negative connotations (Newman, 1990, 1991).
Help seeking may be seen as threatening if the student thinks it is a sign of low ability. In this case, there is a personal cost to seeking help: Students may feel incompetent. Help seeking is positive when students seek assistance in order to make a change in their learning. The attributional process is an important factor in whether help seeking is seen as positive or negative and consequently whether students attend academic help sessions. R. Ames and Lau (1982) identified factors that affected the extent that college students attend help sessions:
Low-performing students were more likely to attend help sessions if they were given specific positive information about the effects of the sessions (e.g., “students who attended improved their performance”).
Students who attributed success to effort were more likely to attend.
Students who did not seek help used more external attributions for failure, such as “tricky test questions,” and used these external reasons as excuses.
Newman’s (1990, 1991) investigations of help seeking among children in Grades 3, 5, and 7 provided a fuller understanding of help seeking. For example, who seeks help, individuals with high or low self-esteem? For all grades, the higher the perceived competence of the children, the less they felt there were personal costs to help seeking (e.g., being thought of as low ability). Students with low self-esteem were especially unlikely to seek help, whereas those with high self-esteem were more likely to seek help. Similar results were obtained by Nelson-Le Gall and Jones (1990) for average-achieving African-American children. Newman (1991) also found differences between younger and older students in views about help seeking. Seventh graders were more aware than younger children that negative fallout might result from help seeking (e.g., embarrassment). However, older children were also more likely than younger ones to believe that smart classmates rather than “dumb” ones ask questions of the teacher. Help seeking by college students showed a pattern similar to that of children. Karabenick and Knapp (1991) found that students with low self-esteem were more threatened by seeking help.
One important and perhaps surprising finding was that students who use more learning strategies are more likely to seek help when needed, whereas students who use fewer strategies are less likely to seek help when needed. This attitude presents a double bind for those needing help. Not only do they lack the necessary strategies for success, but they do not seek the needed study assistance. The authors concluded that students need to learn to judge when they need help and that help seeking should be included in learning strategy and motivation programs. These findings on help seeking are important for teachers and counselors so that they can plan ways to get students to attend help sessions or seek help in counseling when needed. Nelson-Le Gall (1985) emphasized the need to think of help seeking as an adaptive coping strategy rather than as a self-threatening activity. Some ways to accomplish this are listed in Strategy.
Types of Help Seeking
Help seeking behavior is divided into two types, adaptive behavior and non-adaptive behavior. It is adaptive when exercised to overcome a difficulty and it depends upon the person’s recognition, insight and dimension of the problem and resources for solving the same, this is valued as an active strategy. It is non-adaptive when the behavior persists even after understanding and experiencing the problem solving mechanism and when used for avoidance. Dynamic barriers in seeking help can also affect active process (e.g.: culture, ego, classism, etc.). Nelson-Le Gall (1981) distinguished between instrumental help-seeking, which she regarded as being essential for learning, and passive dependency.
Strategy of Help Seeking
The overriding task is to have students view help seeking, when needed, as a smart move instead of a dumb one.
Establish a classroom climate where students are encouraged to ask questions.
Document attendance and improved performance as a result of the help sessions and show this to students.
Be sure students who have improved after attending help sessions attribute the improvement to the help sessions.
Teach students a self-talk script to practice asking teachers for help in classes where they were having problems, as one middle school teacher did.
Meaning of helpless: “Unable to defend oneself or to act without help.” A student who has a history of failure and does not expect this to change will attribute failure to ability an internal and stable factor. This pattern is characteristic of students classified as having learned helplessness. These individuals expect that their actions will be futile in affecting future outcomes. Consequently, they give up. Learned helplessness was first investigated in young animals who had been presented with inescapable electric shocks in one situation; when placed in a different situation, they failed to try to escape or avoid the shock (Seligman & Maier, 1967). Animals that demonstrated no connection between their activity and avoiding the shock had learned to be helpless. It was further hypothesized that humans responded the same way: they were passive in situations where they believed their actions would have no effect on what happens to them. In this original explanation, helplessness was viewed as global affecting all domains of one’s life. Later research found that people may experience helplessness in one situation and not in others (Alloy, Abramson, Peterson, & Seligman, 1984). This means that a student may feel helpless in learning math but not in learning history.
Helplessness exists in achievement situations when students do not see a connection between their actions and their performance and grades. The important aspect of learned helplessness is how it affects the motivational behavior of students in the face of failure. The attributions a student makes for failure act as a bridge between a student’s willingness to try again and the student’s tendency to give up.
Helpless and Mastery Orientation
In a now-classic study, Diener and Dweck (1978) identified two patterns of responses to failure following success in problem-solving tasks: a maladaptive-helpless orientation and an adaptive-mastery orientation. Children showed different response patterns to failure in their thinking, self-talk, affect, and actions. Keep in mind that the students in the study had the same failure experience while performing the tasks, but there were two different patterns of response to the failure outcome. The thinking, self-talk, and actions of the helpless-oriented children formed a self-defeating pattern. When failure is attributed to lack of ability, there is a decline in performance. Attribution to lack of effort does not show this decline (Dweck & Goetz, 1978).
Are there ability differences in learned helplessness? Butkowsky and Willows (1980) compared good, average, and poor readers. They found that poor readers had lower expectancies of success on a reading task. Poor readers overwhelmingly attributed their failures to lack of ability (68% compared with 13% for average readers and 12% for good readers). They took less responsibility for success, attributing success more to task ease an external cause than did the good and average readers. In the face of difficulty, poor readers became less persistent a self-defeating behavior. Helplessness was also found when children studied new material that required them to read passages with confusing concepts.
In a study by Licht and Dweck (1984), half the children received material with a clear passage, and the other half received a confusing passage. There were no differences between mastery orientation and helpless orientation when the passage was clearly written. In contrast, when the passage was not clear, most of the mastery children reached the learning criterion, whereas only one third of the helpless children did. This investigation is important because some academic subjects, like math, are characterized by constant new learning, which may be initially confusing to students. Mastery students will not be discouraged by the initial difficulty, whereas helpless students immediately lose confidence although they may be equally competent. When teaching new material, teachers can be especially alert for this pattern of helplessness in the face of initial difficulty.
Learned Helplessness and Students with Learning Disabilities
Are some students more prone to experience a sense of helplessness? Students particularly susceptible to the pattern of learned helplessness are those students who are identified as having learning disabilities (LD) (Licht, 1983). Children with LD experience much failure over a long period of time on a variety of school tasks. As a result, these children come to doubt their academic abilities, with the accompanying belief that nothing they can do will help them be successful. This is followed by the self-defeating response of decreasing effort. Children with LD have been found to exhibit the following characteristics of the learned helplessness pattern (Licht, 1983):
Score lower than non-LD children on measures of self-esteem and perceptions of ability,
Are more likely to attribute difficulty with tasks to lack of ability,
Are less likely to attribute failure to insufficient effort, and
Lower their expectations for future success and display greater decline in expectation following failure.
It is important for teachers to be aware of the characteristics of helplessness because learned helplessness may explain the students’ apparent lack of motivation. How can a teacher identify a helpless pattern? What can a teacher do to lessen the likelihood of helplessness and help students who have this tendency? Butkowsky and Willows (1980) suggested that educators must begin to rethink failure as a necessary component of the learning process and not as a damaging experience to be avoided.
Does the pattern of learned helplessness show up in young children? Dweck and Sorich (1999) concluded that there is clear evidence of a helplessness pattern in children younger than age 8. After experiencing failure or criticism, they show signs of helplessness like self-blame, lowered persistence, and lack of constructive strategies. Mastery-oriented children, in contrast, assumed they were still good even when their work had errors, and believed they could improve through effort. An important implication for parents and teachers, according to the authors, is to be very cautious when giving feedback to children. Extremely positive or negative feedback can be detrimental to children’s beliefs about their competence.
Understanding of Attribution and Motivation Among Ethnicity?
What is Ethnicity? Meaning of Ethnicity “The fact or state of belonging to a social group that has a common national or cultural tradition.” Some about of Ethnic; Relating to a population subgroup (within a larger or dominant national or cultural group) with a common national or cultural tradition. Relating to national and cultural origins. Denoting origin by birth or descent rather than by present nationality. Characteristic of or belonging to a non-Western cultural tradition.
An ethnic group or ethnicity is a category of people who identify with each other based on similarities, such as common ancestral, language, social, cultural or national experiences. Unlike other social groups (wealth, age, hobbies), ethnicity is often an inherited status based on the society in which one lives. In some cases, it can be adopted if a person moves into another society. Membership of an ethnic group tends to be defined by a shared cultural heritage, ancestry, origin myth, history, homeland, language or dialect, symbolic systems such as religion, mythology and ritual, cuisine, dressing style, art, and physical appearance.
Ethnic groups, derived from the same historical founder population, often continue to speak related languages and share a similar gene pool. By way of language shift, acculturation, adoption and religious conversion, it is sometimes possible for individuals or groups to leave one ethnic group and become part of another (except for ethnic groups emphasizing racial purity as a key membership criterion).
Ethnicity is often used synonymously with ambiguous terms such as nation or people. In English, it can also have the connotation of something exotic (cf. “White ethnic”, “ethnic restaurant”, etc.), generally related to cultures of more recent immigrants, who arrived after the founding population of an area was established.
Now reading – Attribution and Motivation Among Ethnicity; Do attributional explanations for success and failure act as an important motivational force in different ethnic groups? According to Graham (1989,1994), because attributional theory considers the role of thought in determining behavior, it is particularly fruitful in examining motivation in different cultures and ethnic groups.
Beliefs About Effort and Ability
Are attributional belief patterns similar among different ethnic groups? A comparison of poor African-American, Hispanic, Indo-Chinese, and White fifth- and sixth-grade students found similar attribution patterns for all groups (Bempechat, Nakkula, Wu, & Ginsberg, 1996). All groups rated ability as the most important factor for success in math. In a subsequent study comparing African-American, Hispanic, Indo-Chinese, and White fifthand sixth-graders, Bempechat, Graham, and Jimenez (1999) found cultural similarities as well as cultural specifics. For all ethnic groups, failure was attributed to lack of ability and success to external factors. In contrast, Indo-Chinese students had stronger beliefs that failure was due to lack of effort. Attribution for failure due to lack of ability is a problem for all students because it is believed to be uncontrollable.
Graham (1984) compared middle- and low-SES African-American and White students on attributions for failure following a problem-solving task. The middle-class children in both ethnic groups were more likely to attribute failure to lack of effort and maintained consistently higher expectancies for success after experiencing failure. For both groups, this is indicative of an adaptive attributional pattern following failure, similar to that found in research by Diener and Dweck (1978). The findings of this research are important because they demonstrate the positive motivation pattern of African-American students—a pattern that has received little attention.
Stevenson and Lee (1990) compared beliefs of American and Asian students concerning the role of effort and ability for success in mathematics. They asked mothers in Minnesota, Japan, and Taiwan to assign 10 points among ability, effort, task difficulty, and luck to rank their importance in academic success and school performance. All the mothers assigned the points in the same rank order: (1) effort, (2) ability, (3) task, and (4) luck. American mothers scored ability and effort as about equal. In contrast, Taiwanese and Japanese mothers assigned effort a higher value than ability. Peak (1993) noted that, in Japanese elementary schools, ability is rarely mentioned, whereas effort is consistently portrayed as key to success. In contrast, in the United States, students who try very hard are often labeled nerd or grind.
These perceptions of effort and ability take on increased importance when homework is considered in the context of effort. Japanese and Chinese students spend at least twice the amount of time and effort on homework than do American students (Stevenson & Lee, 1990). American teachers assign less and consider it less valuable. Peak (1993) pointed out that homework reflects teachers’ beliefs on whether extra practice makes a difference and whether students are willing to engage in extra effort on behalf of their studies. American parents do not appear to consider good study habits as critical to academic success as do Asian parents.
Implications for Teachers
What can teachers draw from the attributional beliefs among different ethnic groups in terms of classroom practice? The important issue is to understand the motivational processes, such as attribution, operating within a particular ethnic group (Bempechat et al., 1996; Graham, 1994). When similarities are found across ethnic groups, educational interventions do not necessarily have to be targeted to children differentially based on their ethnic group membership.
Graham (1989) emphasized the importance of teacher feedback in influencing concepts of ability and expectations of minority, low-SES students. Recall the previous discussion of indirect attributional cues. It is important to be aware of feedback that may indirectly convey to students that they have low ability. Graham (1994) suggested that in view of the number of African- American children in negative educational situations, it is especially important to be sensitive to how minorities feel, think, and act in response to non-attainment of goals.
How do we decide what caused our success and failure? What cues do we use to explain whether an outcome was influenced by our ability, effort, or some other factor? Information comes from direct and indirect cues (Graham, 1991). Some information comes from direct cues, like failing a test when other students succeeded. Information is also obtained from more indirect cues, often conveyed unintentionally, such as when a teacher communicates pity to a student who failed a test. In addition, there may be a bias toward causes (Weiner, 1992).
Direct Attributional Cues
One of the most important informational cues is the outcome of the task. Here students have a direct cue as to their performance. Another source of attributional information comes from comparing one’s performance to that of others (Weiner, 1992). When most of the class fails a test, students are likely to attribute the failure to the difficulty of the task, not to their ability. However, if Sam failed and everyone else in the class made an A or B, he is likely to believe the failure was due to his low ability. If Sarah fails a test and a peer says, “I didn’t study at all and I made an A,” Sarah may take this as a cue that failure must be due to her ability. When a teacher sees students comparing grades on a test, information other than the test score is being communicated. An important role of the teacher is to help students interpret the possible reasons for test scores and make an adaptive attribution.
Indirect Attributional Cues
In school, feedback that students receive from teachers is a source of much information about ability. Students’ attributional interpretations may be based on the attributions that teachers communicated to them (Reyna, 2000). Graham (1991) identified three groups of feedback as sources of indirect cues: praise versus blame, sympathy versus anger, and help versus neglect.
Praise Versus Blame: The praise or blame a student receives from a teacher can function as an indirect low-ability cue (Graham, 1991). The cue provided by praise or blame interacts with the difficulty of the task and effort expended by a student. Praise acts as a low-ability cue when a student is praised for completing an easy task. A low-ability cue is also conveyed when a student fails a task but receives no blame, like lack of effort. The student can interpret this to mean, “There’s nothing I can do about the failure.”
Sympathy Versus Anger: Did it ever occur to you that communicating sympathy to a student could be interpreted as evidence that he or she has the low ability? Graham (1984) found that when teachers conveyed sympathy following poor student performance, the failing students took this as a cue that they had low ability. Obviously a statement like “I feel sorry for you because you made such a low score” would be a low-ability cue. What might a teacher say that unintentionally conveys a message of low ability to a student? One student remembers a class being told, “All students have to do this except Holly and Ramon.” Holly took her omission as a cue that she would not be able to do the task. In contrast, mild anger for failure can provide an indirect cue that one is capable. For example, “You can do better than this. You handed this paper in with no editing,” provides a cue to the student that he or she is capable of more.
Unsolicited Help: Another low-ability cue for students is unsolicited help by the teacher (Graham & Barker, 1990). Graham and Barker found that, regardless of whether a helper was a peer or teacher, other students judged the student who received unsolicited help as lower in ability than non-helped peers. The important factor in this example is unsolicited. When the teacher consistently gives help to Sylvia before she requests it, this suggests that the teacher knows that she will not be able to do it.
Ability Grouping: One powerful cue for ability that affects large groups of students are tracking according to ability groups. Students in both high and low tracks are defined by labels such as high ability, honors, low-achieving, slow, and average (Oakes, 1985). These labels are powerful cues about one’s ability. Oakes observed that students in the lower track are usually seen by others as dumb and also see themselves in this way. A label may have an adverse effect on students in the high-achieving class as well. Students in a high-track class may take this label as a cue that they naturally have high ability and then assume inflated self-concepts. This belief can interfere with students working to develop their academic skills.
It is important that teachers be aware of the subtle cues that may have unintentional effects on students’ perception of ability. Commonly accepted practices of generous praise, minimal blame, sympathy, and unsolicited help can sometimes be interpreted by students as they have the low ability (M. D. Clark, 1997; Graham, 1991). M. D. Clark found that responses given to students with LD are often interpreted as low-ability cues. Graham further suggested that these cues raise important questions pertinent to the motivation of minority students such as African-Americans. For example, are minority students more likely to be targeted for feedback that conveys sympathy—thus receiving a cue for low ability? Reyna (2000) took this a step further, stating that labeling and indirect cues can lead to stable beliefs about ability and have the negative effect of stereotyping.
Attribution Bias
Attribution bias or Attributional bias is a predisposition to make certain attributional judgments that may be in error (Weiner, 1985). Several variations of attributional bias have been identified that are relevant to achievement settings. A common misjudgment is a hedonic bias, the tendency to attribute success to self rather than to attribute failure to self (Weiner, 2000).
Previous knowledge can also lead to attributions that are erroneous (Frieze, 1980). Potential sources of errors in attributional judgments can be found in stereotypes about certain groups (Reyna, 2000). These preconceptions about certain groups can serve as ready-made explanations for why a student achieves or does not achieve. There is a danger that the stable, uncontrollable attribution for low performance will lead to lower expectations.
The implication for educators is to recognize that a number of possible causes may explain any given success or failure. Thus, it is important to be aware of potential stereotypical attributional biases. Explore other possible causes by gathering more information when bias may be a factor (see Strategy).
Strategy of Collect Attributional Information
Simply ask students why they succeeded, failed, or improved.
Some teachers elicit information by having students give their reasons for how well they did after assignments or exams.
Attribution information can be obtained through the use of learning logs, in which students keep records and write about their goals, successes, and failures.
Conduct an attributional task analysis of student performance. Is it because the student cannot or will not? A teacher may believe that a student is not performing well because he or she has the low ability or is lazy. Instead, the student may be performing low because he or she does not have the essential skills.
Look for clues that will enable you to determine if the student has the essential skills. Does the student have prerequisite knowledge or skills? Does the task require formal reasoning whereas the student is functioning at the concrete reasoning level? Does the student have the necessary learning or memory strategies?
If the student cannot, then teach the prerequisite skill or guide student to the appropriate source of help.
Understanding the Story of All Cavemen Must Carry a Big Stick. Booker T. Washington is credited with the statement, “Success is measured not so much by the position that one has reached in life as by the obstacles which he had to overcome while trying to succeed.”
All Cavemen Must Carry a Big Stick
Once, I was a guest on a talk radio show along with Michael McDonald, one of my students who had pulled himself out of the ghetto to become an attorney and a respected politician. Michael had done this despite seemingly overwhelming odds that were stacked against him. Mike was asked by the host why others also do not likewise pull themselves up by their own bootstraps. He replied that it was really tough to pull yourself up by your bootstraps when you had no boots. What a great answer. No matter what the Preamble to our Constitution states, all men (and women) are not created equal.
We each are born into different environments, with different talents, financial means, intelligence levels and other distinct advantages… or disadvantages. Why do some, like Mike, despite the odds, manage to succeed? Why do some have different drives, ambition, attitudes and determination? When is all this determined? Is it in the womb or the first few years of life? The great speaker, Zig Ziglar says, “Great people are just ordinary people with extraordinary determination.”Man Cave Store, Over the years, I have found this to be true.
I taught high school for sixteen and one-half years. As I reflect back on the kids that I taught, the ones that accomplished the most in life were the ones that I would never have selected to do so. They were the ones that were average kids with little opportunity and lots of drive, grit and determination. When our caveman friend went out to go hunting, he soon learned that to bring the game home, he had to carry a big stick and learn how to use it. They too had to learn to carry a big stick and lots of arrows in their quiver. Here are Cavemen’s stories.
Cavemen Story One:
Bob graduated from high school with less than average grades. Never did he, or anyone else, expect him to go to college. He met their expectations by starting to work immediately after high school. Although he did not like school, he was really good working with his hands. He liked the immediate gratification of seeing his projects come to fruition. He enjoyed construction work and began his first job as a carpenter’s helper.
In a few years, he borrowed money from a local bank and built his first house. Then, he built another…then another. Fifteen years after graduation, he built his first condominium and found that he could quadruple his return by building and reselling multiple units. Bob is now a millionaire but continues to build condominiums and commercial properties.
Cavemen Story Two:
Eric, like Bob in the first Cavemen story, barely graduated from high school. If a vote was taken, he would have been selected as the most likely not to succeed. Also, like Bob, he enjoyed working with his hands. His first few jobs were working as a helper for an auto mechanic. He started working part time in construction and learned fast. He enjoyed the challenge and satisfaction of seeing a project completed. Before long, Eric quit his job as a mechanic’s helper and built his first house.
Eric moved into the house an immediately began his second house. … then a third. … then a fourth. Before long, he was developing subdivisions in his hometown. He negotiated and signed a contract to build grocery stores all across the country for a regional food store chain. The rest is history. Eric is now a multi-millionaire and travels the world expanding his investments and counting his money.
Cavemen Story Three:
Tom graduated from high school in the middle of his class. He was average at best and never attempted to go to college. Instead, he started to work selling televisions at a retail store in a strip mall not far from home. Tom enjoyed sales and got very good at it. While others were in college classes, Tom was learning from the school of hard knocks. He eventually left his job selling televisions and started to work as a salesman for an electronic company that supplied components to the company that manufactured the television sets.
By the time that Tom’s classmates graduated from college and began to join the workforce, Tom had managed to buy the troubled electronics company. Before long, through Tom’s diligence, determination and perseverance, the company had recovered, and Tom sold it to his biggest competitor. He immediately reinvested his profits into other ventures, which included several radio stations, a restaurant chain and a regional health club chain. Tom now lives in one of the biggest houses in town and spends most of his time playing with his diversified portfolio.
Story Four:
John graduated from high school as the class favorite. He was always well-liked and popular. Most were surprised when John did not go to college. He, instead, started to work with his brother-in-law building commercial properties. They soon discovered that they could build high-rise apartments for government housing at hefty profits.
One thing followed another and soon their company had grabbed the attention of others who wanted to purchase the company. Not long after, John and his brother-in-law sold the business and both retired. Since he was forty-years-old, John has done exactly what he wants to do each day. He has not worked in many years.
Story Five:
Our fifth Cavemen story is the story of Mike McDonald, the young man mentioned earlier in this chapter. I take special pride in Mike’s story since I did play a small part in opening a door to get Mike started. Mike was a great kid in high school. Mike lived in the government housing projects and had witnessed many of the personal tragedies of others growing up there. He stood exposed at an early age to gangs, drugs, violence and crime.
Mike was smart enough to remove himself from those who were bad influences on him. Mike was active in his church, played on the high school football team and made good grades. Upon graduation, he knew that the likelihood of a college education was not good. This is where I enter the picture.
Mike had a job working at one of the Taco Bells in Huntsville. As fate would have it, one day I got a craving for a spicy bean burrito. When I entered the Taco Bell I saw Mike sweeping the floors. I asked him why he was not in college. After a short conversation and three burritos, I promised Mike that I would see if I could help him get into college. A few phone calls to Middle Tennessee State University and to State Farm Insurance in Murfreesboro, Tennessee, things were beginning to fall into place. I had worked my way through school at MTSU by working in the mail room at State Farm Insurance’s South Central Office.
It was mere luck (Remember what I said about luck.) that the personnel manager remembered me (Although it had been nearly ten years.) and agreed to give Mike a job. A few weeks later, Mike was enrolled in MTSU and had a steady job at State Farm Insurance. He caught a greyhound bus to Murfreesboro with only ten dollars in his pocket. Four years later, he graduated with honors from MTSU and entered law school. While at MTSU, Mike earned a position as a split receiver on the football team and was the first black President of the student body.
Since graduating, Mike has stood named the Most Outstanding Alumni and earned many post-graduate honors. One of his first jobs was as the legal counsel to the Governor of the state of Tennessee. He was later Registrar of Davidson County (Nashville), Tennessee where he served for many years. At this writing, Mike is an attorney in Nashville and a law professor at two universities, MTSU and Tennessee State University. Mike’s success truly touches my heart since he had the least opportunity of any student that I encountered yet, he accomplished the most.
All of the above stories are true. Of those mentioned, only Mike McDonald had a college education. What did all the people in the stories above have in common? They all had determination, an overwhelming desire to achieve and great work ethic. They each overcame the odds to attain the things that each accomplished. As stated earlier in this book, work ethic is more important than a stack of college degrees. In the Cavemen stories above, each learned to carry a big stick, to fill their quiver, and they each had a passion for what they did.
Here is a short story about determination:
Cavemen stories, A young guard stood placed on guard duty for the first time. He stood instructed that no vehicle was allowed to enter the compound unless it had a certain identification number on it. As luck would have it, the first unmarked vehicle to approach the gate was that of a general. The General had total disregard for the young guard and instructed his driver to drive on through the gate. The young guard leaned inside the vehicle and politely stated, “I’m new at this, sir, and I really don’t know what to do. Who do I shoot first, you or the driver?”
Several years ago at the National Spelling Bee, one of the young ladies really excelled among the others in the competition. With a bright smile, she confidently spelled each word without hesitation. After she had won the contest, she was being interviewed by the television network and was asked how she became just an outstanding speller. She looked directly into the camera and stated, “My success is due to two things, God and Practice!”
I spent the first sixteen and one-half years of my working life as an educator. Two particular coaches really stand out in my mind. One fellow would practice his football team hour upon hour, day upon day, week upon week. He would practice his team on weekends and holidays. His practice time ran for hours with disgruntled parents waiting in the parking lot to pick up their kids. He was known far and near as being a tough and demanding coach, a reputation which he treasured. His players seemed to always suffer from burnout and bad attitudes. This coach was known throughout the state as being a tough coach. The problem was he could never produce a championship team. In fact, he often struggled just to have a winning season! Then there was coach number two.
Coach number two had a whole different philosophy. His practice times were short but compact. The attitudes among his players were great. Every drill had a purpose. His practice time was filled with fun things that developed skills and motivated his athletes. The parents of his athletes loved him; the school board loved him; the Booster Club loved him; and his players loved him. He was always in demand as a public speaker at civic clubs and coaching clinics. Guess what? He also always produced the best teams, winning seasons, and led the conference in athletic scholarships for his players.
What was the difference in these two coaches? Coach number two had learned the secret of success. Contrary to Ben Franklin or whoever gets credit for the old saying… practice does not make perfect. Only “good” practice makes perfect! If a person does the same thing over and ever and over, but does it the wrong way, it is still wrong. That person is wasting his time, spinning his wheels and reinforcing the negative. A person has to determine the things that work and concentrate on strengthening and improving the little things that will enhance their success ratio. Doing the same thing over and over will produce the same results. If something is not working, then evaluate it (Remember the principals of management?), and make adjustments so that the results will be different. In the world in which we live, the winners have learned to do this whether it is in one’s personal life, business life, hobbies or in coaching!
A person can find true peace and self-actualization through accomplishment. On the other hand, continuous failure leads to a very sad and unfulfilling life. There are so many people who continue to live their lives in a rut that leads to nowhere. They work in jobs that they do not like, with people that they cannot tolerate and in positions that are unrewarding. This is so sad since life is full of opportunity, excitement and adventure. Why would anyone stay in a situation in which they merely exist instead of flourish? Life has too much to offer for one to waste away his precious years and trade each day of his life for a paycheck! That is why entrepreneurs are different from other people. There is something in their inner being that will not allow them to merely survive.
Zig Ziglar has inspired thousands upon thousands with his books and public appearances. I had the opportunity to meet Mr. Ziglar several years ago and found him to be even more dynamic in person as he is in his books and on his tapes. Zig believes, as I do, that a good attitude is the most important personal asset that a person possesses. One’s outlook on life determines how far he will go. One’s attitude determines how one reacts to the inevitable failures that even the most successful people have to overcome. As Zig states, “It’s not what happens to you that is important, but rather how you react to what happens to you.” How true this statement is! When things don’t go right, do you fall apart? Do you lash out and blame others? Do you wallow in your failure or do you pick yourself up, dust yourself off and continue to plunge forward? We have all heard the stories of Thomas Edison and the number of times that he suffered defeat and setbacks in his endeavor to invent the light bulb and some of his other inventions. We have all heard the stories of Col. Harland Sanders and how he only found success with his Kentucky Fried Chicken idea after he retired from what he really did for a living. We have heard the story of Garth Brooks who was rejected time and time again by the major record labels in Nashville before a chance appearance at the Bluebird Café turned his life around. Garth went on to be the biggest single country act in history! These type stories go on and on. Zig states that, “One’s attitude, not his aptitude, will determine his altitude.” How true this statement is for the aspiring entrepreneur?
Over the years, I have discovered that entrepreneurs have a different outlook on life. There is the story about the young clerk in the department store who was approached by a customer who asked him if he was the manager. The young man looked up at the customer and quickly replied, “No sir! Not yet!” What a great answer! Just imagine if the young man had hanged his head and replied, “Oh no sir. Not me. I’m just a clerk.” What a different image that would have projected. There is another story about the two men who were both working side by side digging a ditch that was to be the foundation for a huge new palace. A passerby stopped and asked the first man what he was doing. Belligerently, he replied, “Can’t you see that I’m digging a ditch?” The passerby continued over to the second man and stated, “Well, I see that you are digging a ditch also.” “No sir”, replied the second man. “I’m building a palace!” Attitude! Attitude! Attitude!
Once, several years ago, I was watching one of the local television stations in my home town of Huntsville, Alabama. The local news had had a contest among the regional junior high school students and had selected one of the students to co-host the weather forecast. The young man that won the contest gave his weather report along with the station’s meteorologist. After the report, the meteorologist conducted a quick interview with the young man. He asked him about his education and future ambitions. The meteorologist concluded his interview by asking him if one day he wanted to be the weatherman at the station. The young man paused, and with a perplexed look on his face replied, “No sir! One day I want to own this station!” I could not help but get a lump in my throat when I heard his answer. That is the attitude that this country desperately needs! Why work at the station when you can own the station? That is the mindset of the entrepreneur.
The caveman was the world’s first real entrepreneur. He had no choice. Either he got up, got his club, wandered into the woods, set his traps, killed something and drug it home each day, or he starved. He had to be able to out-run the fastest saber tooth tiger or he perished. There were no guaranteed salaries, pension plans, 401K’s, trade unions to protect him, deferred compensation programs, life and health benefit programs or Christmas turkeys or bonuses. The caveman had to perform each day, every day by the sweat of his brow and with his two hands and wit or he would not survive. Were there some cavemen who survived better and longer than others?
A caveman is a stock character based upon widespread but anachronistic and conflated concepts of the way in which Neanderthals, early modern humans, or archaic humans may have looked and behaved. The term originates out of assumptions about the association between early humans and caves, most clearly demonstrated in cave painting. The term is not used in academic research.
Sure there were! Some hunted longer, ran faster, got up earlier, learned to set better traps, learned to preserve their foods and prospered better than the others. These cavemen had the prettiest women, wore warmer furs, had better caves, bigger clubs and were envied and copied by the other cave people. Since mankind first came upon the earth, there were those who learned to excel over others. There always have been those who, through their willingness to take calculated risks, work harder, work smarter, work longer, develop their skills and improve themselves, achieve when others fail. This is true in the animal world. The biggest and strongest buck gets the doe. The fastest gazelle is never eaten by the lion. The smartest mouse is never caught in the trap no matter how large the cheese appears to be!
Nothing has changed today except that the mentality of the caveman has been absolved by today’s modern world. Most people today would starve to death if they had to survive by killing something and dragging it home every day. Most would starve if they had to really work to make a living. Many todays had rather live with tremendous debt, work in jobs that they hate and with people that they despise and live in houses that they cannot afford than to roll up their sleeves and change their condition in life.
Today, it is hard to listen to the radio without occasionally stumbling into one of those financial gurus on the talk radio stations out there. On every show, someone will call in to ask advice on the matter of personal bankruptcy. This person is always in debt because he has established habits of making one poor choice after another. He always has lived in houses that he could not afford, attended college on borrowed money, bought automobiles when he should have been walking and built up credit card and personal debt that was larger than his annual income. All of these callers want to declare bankruptcy. They are seeking advice as to how to get the process started. Almost none of them are willing to do the things necessary to eliminate the debt. What? Work two jobs! Nonsense! Work out a payment plan to systematically eliminate the debt. Not me! They just want to know how to wipe out the debt that they, under legal contract, legitimately owe. By doing so, they cross the magic threshold that converts them from a consumer to a thief!
They are technically robbing a bank! They are absolutely no different than the person who straightens his mask, sticks a gun in a teller’s face then runs to a get-away car. They are doing exactly the same thing except that the bank robber deserves more respect since he is more honest in his intentions. A thief is someone who knowingly and willingly steals from others. If we would today again implement debtor’s prisons, there is no doubt that personal debt would drop to near zero. Mankind has become accustomed to the cushions afforded by this society. Today, there are few consequences for a person’s actions. Because of this, the caveman mentality of eat or be eaten has been lost. As our bankruptcy courts have proven, many have become lazy and had rather steal than to actually work to change their condition. What is as disappointing is that society has accepted this and places little or no shame on the actions of these people!
This post is addressed to those who, like the cavemen of long ago, want to enter the world of entrepreneurship. This is a great country with opportunity hanging before each of us like a ripe, red apple ready for picking. There is no better place to be in the universe for those who want to enter the world of entrepreneurship. That world is not for the lazy, fainthearted, weak or unstable. It is for those who are willing to run ahead of the racers, to work longer, harder, faster and smarter. It is for those who are willing to break tradition, to color outside of the lines, to stand straight, to square their shoulders, swallow hard and kill something for the pot each and every day. It is for those who are not willing to live like everyone else. It is for those who do not want to be normal. It is for those who want to lift themselves above the crowd and, by their own two hands, shape and direct their future. If you fit this mold, then get on your feet, pick up your club, follow us as we welcome you to the brotherhood of the caveman and the greatest adventure of your life!
Some organisms, such as plants, can trap the energy in sunlight through photosynthesis (see Photosynthesis) and store it in the chemical bonds of carbohydrate molecules. The principal carbohydrate formed through photosynthesis is glucose. Other types of organisms, such as animals, fungi, many protozoa, and a large portion of bacteria, are unable to perform this process. Therefore, these organisms must rely on the carbohydrates formed in plants to obtain the energy necessary for their metabolic processes.
Animals and other organisms obtain the energy available in carbohydrates through the process of cellular respiration. Cells take the carbohydrates into their cytoplasm, and through a complex series of metabolic processes, they break down the carbohydrates and release the energy. The energy is generally not needed immediately; rather, it is used to combine adenosine diphosphate (ADP) with phosphate ions to form adenosine triphosphate (ATP) molecules. The ATP can then be used for processes in the cells that require energy, much as a battery powers a mechanical device.
During the process of cellular respiration, carbon dioxide is given off. This carbon dioxide can be used by plant cells during photosynthesis to form new carbohydrates. Also in the process of cellular respiration, oxygen gas is required to serve as an acceptor of electrons. This oxygen is identical to the oxygen gas given off during photosynthesis. Thus, there is an interrelationship between the processes of photosynthesis and cellular respiration, namely the entrapment of energy available in sunlight and the provision of the energy for cellular processes in the form of ATP.
The overall mechanism of cellular respiration involves four processes: glycolysis, in which glucose molecules are broken down to form pyruvic acid molecules; the Krebs cycle, in which pyruvic acid is further broken down and the energy in its molecule is used to form high-energy compounds, such as nicotinamide adenine dinucleotide (NADH); the electron transport system, in which electrons are transported along a series of coenzymes and cytochromes and the energy in the electrons is released; and chemiosmosis, in which the energy given off by electrons pumps protons across a membrane and provides the energy for ATP synthesis. The general chemical equation for cellular respiration is:
C6H12O6 + 6 O2 → 6 H2O + 6CO2 + energy
Figure 1. provides an overview of cellular respiration. Glucose is converted to pyruvic acid in the cytoplasm, which is then used to produce acetyl CoA in the mitochondrion. Finally, the Krebs cycle proceeds in the mitochondrion. Electron transport and chemiosmosis result in energy release; ATP synthesis also occurs in the mitochondrion.
Glycolysis
Glycolysis is the process in which one glucose molecule is broken down to form two molecules of pyruvic acid (also called pyruvate). The glycolysis process is a multi-step metabolic pathway that occurs in the cytoplasm of animal cells, plant cells, and the cells of microorganisms. At least six enzymes operate in the metabolic pathway.
In the first and third steps of the pathway, ATP energizes the molecules. Thus, two ATP molecules must be expended in the process. Further along in the process, the six-carbon glucose molecule converts into intermediary compounds and is then split into two three-carbon compounds. The latter undergo additional conversions and eventually form pyruvic acid at the conclusion of the process.
During the latter stages of glycolysis, four ATP molecules are synthesized using the energy given off during the chemical reactions. Thus, four ATP molecules are synthesized and two ATP molecules are used during glycolysis, for a net gain of two ATP molecules.
Figure 1. An overview of cellular respiration.
Another reaction during glycolysis yields enough energy to convert NAD to NADH (plus a hydrogen ion). The reduced coenzyme (NADH) will later be used in the electron transport system, and its energy will be released. During glycolysis, two NADH molecules are produced.
Because glycolysis does not require oxygen, the process is considered to be anaerobic. For certain anaerobic organisms, such as some bacteria and fermentation yeasts, glycolysis is the sole source of energy.
Glycolysis is a somewhat inefficient process because much of the cellular energy remains in the two molecules of pyruvic acid that are created. Interestingly, this process is somewhat similar to a reversal of photosynthesis (see Photosynthesis).
Krebs Cycle
Following glycolysis, the mechanism of cellular respiration involves another multi-step process—the Krebs cycle, which is also called the citric acid cycle or the tricarboxylic acid cycle. The Krebs cycle uses the two molecules of pyruvic acid formed in glycolysis and yields high-energy molecules of NADH and Flavin adenine dinucleotide (FADH2), as well as some ATP.
Krebs Cycle
The Krebs cycle occurs in the mitochondrion of a cell (see Figure 6). This sausage-shaped organelle possesses inner and outer membranes and, therefore, inner and outer compartments. The inner membrane is folded over itself many times; the folds are called cristae. They are somewhat similar to the thylakoid membranes in chloroplasts (see Photosynthesis). Located along the cristae are the important enzymes necessary for the proton pump and for ATP production.
Prior to entering the Krebs cycle, the pyruvic acid molecules are altered. Each three-carbon pyruvic acid molecule undergoes conversion to a substance called acetyl-coenzyme A, or Acetyl-CoA. During the process, the pyruvic acid molecule is broken down by an enzyme, one carbon atom is released in the form of carbon dioxide, and the remaining two carbon atoms are combined with a coenzyme called coenzyme A. This combination forms Acetyl-CoA. In the process, electrons and a hydrogen ion are transferred to NAD to form high-energy NADH.
Acetyl-CoA enters the Krebs cycle by combining with a four-carbon acid called oxaloacetic acid. The combination forms the six-carbon acid called citric acid. Citric acid undergoes a series of enzyme-catalyzed conversions. The conversions, which involve up to ten chemical reactions, are all brought about by enzymes. In many of the steps, high-energy electrons are released to NAD. The NAD molecule also acquires a hydrogen ion and becomes NADH. In one of the steps, FAD serves as the electron acceptor, and it acquires two hydrogen ions to become FADH2. Also, in one of the reactions, enough energy is released to synthesize a molecule of ATP. Because for each glucose molecule there are two pyruvic acid molecules entering the system, two ATP molecules are formed.
Also during the Krebs cycle, the two carbon atoms of Acetyl-CoA are released, and each forms a carbon dioxide molecule. Thus, for each Acetyl-CoA entering the cycle, two carbon dioxide molecules are formed. Two Acetyl-CoA molecules enter the cycle, and each has two carbon atoms, so four carbon dioxide molecules will form. Add these four molecules to the two carbon dioxide molecules formed in the conversion of pyruvic acid to Acetyl-CoA, and it adds up to six carbon dioxide molecules. These six CO2 molecules are given off as waste gas in the Krebs cycle. They represent the six carbons of glucose that originally entered the process of glycolysis.
At the end of the Krebs cycle, the final product is oxaloacetic acid. This is identical to the oxaloacetic acid that begins the cycle. Now the molecule is ready to accept another Acetyl-CoA molecule to begin another turn of the cycle. All told, the Krebs cycle forms (per two molecules of pyruvic acid) two ATP molecules, ten NADH molecules, and two FADH2 molecules. The NADH and the FADH2 will be used in the electron transport system.
Electron Transport System
The electron transport system occurs in the cristae of the mitochondria, where a series of cytochromes (enzymes) and coenzymes exist. These cytochromes and coenzymes act as carrier molecules and transfer molecules. They accept high-energy electrons and pass the electrons to the next molecule in the system. At key proton-pumping sites, the energy of the electrons transports protons across the membrane into the outer compartment of the mitochondrion.
Each NADH molecule is highly energetic, which accounts for the transfer of six protons into the outer compartment of the mitochondrion. Each FADH2 molecule accounts for the transfer of four protons. The flow of electrons is similar to that taking place in photosynthesis. Electrons pass from NAD to FAD, to other cytochromes and coenzymes, and eventually they lose much of their energy. In cellular respiration, the final electron acceptor is an oxygen atom. In their energy-depleted condition, the electrons unite with an oxygen atom. The electron-oxygen combination then reacts with two hydrogen ions (protons) to form a water molecule (H2O).
The role of oxygen in cellular respiration is substantial. As a final electron acceptor, it is responsible for removing electrons from the electron transport system. If oxygen were not available, electrons could not be passed among the coenzymes, the energy in electrons could not be released, the proton pump could not be established, and ATP could not be produced. In humans, breathing is the essential process that brings oxygen into the body for delivery to the cells to participate in cellular respiration.
Chemiosmosis
The actual production of ATP in cellular respiration takes place through the process of chemiosmosis (see Cells and Energy). Chemiosmosis involves the pumping of protons through special channels in the membranes of mitochondria from the inner to the outer compartment. The pumping establishes a proton (H+) gradient. After the gradient is established, protons diffuse down the gradient through a transport protein called ATP synthase. The flow of hydrogens catalyzes the pairing of a phosphate with ADP, forming ATP.
The energy production of cellular respiration is substantial. Most biochemists agree that 36 molecules of ATP can be produced for each glucose molecule during cellular respiration as a result of the Krebs cycle reactions, the electron transport system, and chemiosmosis. Also, two ATP molecules are produced through glycolysis, so the net yield is 38 molecules of ATP. These ATP molecules may then be used in the cell for its needs. However, the ATP molecules cannot be stored for long periods of time, so cellular respiration must constantly continue in order to regenerate the ATP molecules as they are used. Each ATP molecule is capable of releasing 7.3 kilocalories of energy per mole.
Fermentation
Fermentation is an anaerobic process in which energy can be released from glucose even though oxygen is not available. Fermentation occurs in yeast cells, and a form of fermentation takes place in bacteria and in the muscle cells of animals.
In yeast cells (the yeast used for baking bread and producing alcoholic beverages), glucose can be metabolized through cellular respiration as in other cells. When oxygen is lacking, however, glucose is still metabolized to pyruvic acid via glycolysis. The pyruvic acid is converted first to acetaldehyde and then to ethyl alcohol. The net gain of ATP to the yeast cell is two molecules—the two molecules of ATP normally produced in glycolysis.
Yeasts are able to participate in fermentation because they have the necessary enzyme to convert pyruvic acid to ethyl alcohol. This process is essential because it removes electrons and hydrogen ions from NADH during glycolysis. The effect is to free the NAD so it can participate in future reactions of glycolysis. The net gain to the yeast cell of two ATP molecules permits it to remain alive for some time. However, when the percentage of ethyl alcohol reaches approximately 15 percent, the alcohol kills the yeast cells.
Yeast is used in both bread and alcohol production. Alcohol fermentation is the process that yields beer, wine, and other spirits. The carbon dioxide given off during fermentation supplements the carbon dioxide given off during the Krebs cycle and causes bread to rise.
In muscle cells, another form of fermentation takes place. When muscle cells contract too frequently (as in strenuous exercise), they rapidly use up their oxygen supply. As a result, the electron transport system and Krebs cycle slow considerably, and ATP production is slowed. However, muscle cells have the ability to produce a small amount of ATP through glycolysis in the absence of oxygen. The muscle cells convert glucose to pyruvic acid. An enzyme in the muscle cells then converts the pyruvic acid to lactic acid. As in the yeast, this reaction frees up the NAD while providing the cells with two ATP molecules from glycolysis. Eventually, however, the lactic acid buildup causes intense fatigue, and the muscle stops contracting.
A great variety of living things on Earth, including all green plants, synthesize their foods from simple molecules, such as carbon dioxide and water. For this process, the organisms require energy, and that energy is derived from sunlight.
Figure 1. shows the energy relationships in living cells. Light energy is captured in the chloroplast of plant cells and used to synthesize glucose molecules, shown as C6H12O6. In the process, oxygen (O2) is released as a waste product. The glucose and oxygen are then used in the mitochondrion of the plant cell, and the energy is released and used to fuel the synthesis of ATP from ADP and P. In the reaction, CO2 and water are released in the mitochondrion to be reused in photosynthesis in the chloroplast.
Energy relationships in living cells Cycles
Figure 1. Energy relationships in living cells.
The process of utilizing energy to synthesize carbohydrate molecules is called photosynthesis. Photosynthesis is actually two separate processes. in the first process, energy-rich electrons flow through a series of coenzymes and other molecules. This electron energy is trapped. During the trapping process, adenosine triphosphate (ATP) molecules and molecules of nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) are formed. Both ATP and NADPH are rich in energy. These molecules are used in the second process, where carbon dioxide molecules are bound into carbohydrates too form organic substances such as glucose.
Chloroplast
The organelle in which photosynthesis occurs (in the leaves and green stems of plants, for example) is called the chloroplast. Chloroplasts are relatively large organelles, containing a watery, protein-rich fluid called stroma. The stroma contains many small structures composed of membranes that resemble stacks of coins. Each stack is a granum (the plural form is grana). Each membrane in the stack is a thylakoid. Within the thylakoid membranes of the granum, many of the reactions of photosynthesis take place. The thylakoids are somewhat similar to the cristae of mitochondria (see Cellular Respiration).
Photosystems
Pigment molecules organized into photosystems capture sunlight in the chloroplast. Photosystems are clusters of light-absorbing pigments with some associated molecules—proton (hydrogen ion) pumps, enzymes, coenzymes, and cytochromes (see Cells and Energy). Each photosystem contains about 200 molecules of a green pigment called chlorophyll and about 50 molecules of another family of pigments called carotenoids. In the reaction center of the photosystem, the energy of sunlight is converted to chemical energy. The center is sometimes called a light-harvesting antenna.
There are two photosystems within the thylakoid membranes, designated photosystem I and photosystem II. The reaction centers of these photosystems are P700 and P680, respectively. The energy captured in these reaction centers drives chemiosmosis, and the energy of chemiosmosis stimulates ATP production in the chloroplasts.
Process of Photosynthesis
The process of photosynthesis is conveniently divided into two parts: the energy-fixing reaction (also called the light reaction) and the carbon-fixing reaction (also called the light-independent reaction or the dark reaction).
Energy-fixing reaction
The energy-fixing reaction of photosynthesis begins when light is absorbed in photosystem II in the thylakoid membranes. The energy of the sunlight, captured in the P680 reaction center, causes the electrons from P680’s chlorophyll to move to a higher, unstable energy level. These electrons pass through a series of cytochromes in the nearby electron-transport system.
After passing through the electron transport system, the energy-rich electrons eventually enter Photosystem-I. Some of the energy of the electron is used to pump protons across the thylakoid membrane, and this pumping sets up the potential for chemiosmosis.
The spent electrons from P680 enter the P700 reaction center in photosystem I. Sunlight activates the electrons, which receive a second boost out of the chlorophyll molecules. There they reach a high energy level. The electrons progress through a second electron transport system, but this time there is no proton pumping. Rather, the energy reduces NADP. This reduction occurs as two electrons join NADP and energize the molecule. Because NADP acquires two negatively charged electrons, it attracts two positively charged protons to balance the charges. Consequently, the NADP molecule is reduced to NADPH, a molecule that contains much energy.
Because electrons have flowed out of the P680 reaction center, the chlorophyll molecules are left without a certain number of electrons. Electrons secured from water molecules replace these electrons. Each split water molecule releases two electrons that enter the chlorophyll molecules to replace those lost. The split water molecules also release two protons that enter the cytoplasm near the thylakoid and are available to increase the chemiosmotic gradient.
The third product of the split water molecules is oxygen. Two oxygen atoms combine with one another to form molecular oxygen (O2), which is given off as the by-product of photosynthesis; it fills the atmosphere and is used by all oxygen-requiring organisms, including plant and animal cells.
Described above are the noncyclic energy-fixing reactions (see Figure 2). Certain plants and autotrophic prokaryotes are also known to participate in cyclic energy-fixing reactions. These reactions involve only photosystem I and the P700 reaction center. Excited electrons leave the reaction center, pass through coenzymes of the electron transport system, and follow a special pathway back to P700. Each electron powers the proton pump and encourages the transport of a proton across the thylakoid membrane. This process enriches the proton gradient and eventually leads to the generation of ATP.
Figure 2. The energy-fixing reactions of photosynthesis.
ATP production in the energy-fixing reactions of photosynthesis occurs by the process of chemiosmosis (explained in Cells and Energy). Essentially, this process consists of a rush of protons across a membrane (the thylakoid membrane, in this case), accompanied by the synthesis of ATP molecules. Biochemists have calculated that the proton concentration on one side of the thylakoid is 10,000 times that of the opposite side of the membrane.
In photosynthesis, the protons pass back across the membranes through channels lying alongside sites where enzymes are located. As the protons pass through the channels, the energy of the protons is released to form high-energy ATP bonds. ATP is formed in the energy-fixing reactions along with the NADPH formed in the main reactions. Both ATP and NADPH provide the energy necessary for the synthesis of carbohydrates that occurs in the second major set of events in photosynthesis.
Carbon-fixing reaction
Glucose and other carbohydrates are synthesized in the carbon-fixing reaction of photosynthesis, often called the Calvin cycle after Melvin Calvin, who performed much of the biochemical research (see Figure 3). This phase of photosynthesis occurs in the stroma of the plant cell.
A carbon-fixing reaction or the Calvin cycle
Figure 3. A carbon-fixing reaction, also called the Calvin cycle.
In the carbon-fixing reaction, an essential material is carbon dioxide, which is obtained from the atmosphere. The carbon dioxide is attached to a five-carbon compound called ribulose bisphosphate. Ribulose bisphosphate carboxylase catalyzes this reaction.
After carbon dioxide has been joined to ribulose bisphosphate, a six-carbon product forms, which immediately breaks into two three-carbon molecules called phosphoglycerate. Each phosphoglycerate molecule converts to another organic compound, but only in the presence of ATP. The ATP used is the ATP synthesized in the energy-fixing reaction. The organic compound formed converts to still another organic compound using the energy present in NADPH. Again, the energy-fixing reaction provides the essential energy. Each of the organic compounds that results consists of three carbon atoms. Eventually, the compounds interact with one another and join to form a single molecule of six-carbon glucose. This process also generates additional molecules of ribulose bisphosphate to participate in further carbon-fixing reactions.
Glucose can be stored in plants in several ways. In some plants, the glucose molecules are joined to one another to form starch molecules. Potato plants, for example, store starch in tubers (underground stems). In some plants, glucose converts to fructose (fruit sugar), and the energy is stored in this form. In still other plants, fructose combines with glucose to form sucrose, commonly known as table sugar. The energy is stored in carbohydrates in this form. Plant cells obtain energy for their activities from these molecules. Animals use the same forms of glucose by consuming plants and delivering the molecules to their cells.
All living things on Earth depend in some way on photosynthesis. It is the main mechanism for bringing the energy of sunlight into living systems and making that energy available for the chemical reactions taking place in cells.
The Laws of Thermodynamics; Life can exist only where molecules and cells remain organized. All cells need energys to maintain organization. Physicists define energy as the ability to do work; in this case, the work is the continuation of life itself.
Energy has been expressed in terms of reliable observations known as the laws of thermodynamics. There are two such laws. The first law of thermodynamics states that energy can neither be created nor destroyed. This law implies that the total amount of energy in a closed system (for example, the universe) remains constant. Energys neither enters nor leaves a closed system.
Within a closed system, energy can change, however. For instance, the chemical energy in gasoline is released when the fuel combines with oxygen and a spark ignites the mixture within a car’s engine. The gasoline’s chemical energy is changed into heat energy, sound energy, and the energy of motion.
The second law of thermodynamics states that the amount of available energy in a closed system is decreasing constantly. Energy becomes unavailable for use by living things because of entropy, which is the degree of disorder or randomness of a system. The entropy of any closed system is constantly increasing. In essence, any closed system tends toward disorganization.
Unfortunately, the transfers of energy in living systems are never completely efficient. Every body movement, every thought, and every chemical reaction in the cells involves a shift of energy and a measurable decrease of energy available to do work in the process. For this reason, considerably more energy must be taken into the system than is necessary to carry out the actions of life.
Chemical Reactions
Most chemical compounds do not combine with one another automatically, nor do chemical compounds break apart automatically. The great majority of the chemical reactions that occur within living things must be energized. This means that the atoms of a molecule must be separated by energy put into the system. The energy forces apart the atoms in the molecules and allows the reaction to take place.
To initiate a chemical reaction, a type of “spark,” referred to as the energy of activation, is needed. For example, hydrogen and oxygen can combine to form water at room temperature, but the reaction requires activation energy.
Any chemical reaction in which energy is released is called an exergonic reaction. In an exergonic chemical reaction, the products end up with less energy than the reactants. Other chemical reactions are endergonic reactions. In endergonic reactions, energy is obtained and trapped from the environment. The products of endergonic reactions have more energy than the reactants taking part in the chemical reaction. For example, plants carry out the process of photosynthesis, in which they trap energy from the sun to form carbohydrates (see Photosynthesis).
The activation energy needed to spark an exergonic or endergonic reaction can be heat energy or chemical energy. Reactions that require activation energy can also proceed in the presence of biological catalysts. Catalysts are substances that speed up chemical reactions but remain unchanged themselves. Catalysts work by lowering the required amount of activation energy for the chemical reaction. For example, hydrogen and oxygen combine with one another in the presence of platinum. In this case, platinum is the catalyst. In biological systems, the most common catalysts are protein molecules called enzymes. Enzymes are absolutely essential if chemical reactions are to occur in cells.
Enzymes
The chemical reactions in all cells of living things operate in the presence of biological catalysts called enzymes. Because a particular enzyme catalyzes only one reaction, there are thousands of different enzymes in a cell catalyzing thousands of different chemical reactions. The substance changed or acted on by an enzyme is its substrate. The products of a chemical reaction catalyzed by an enzyme are end products.
All enzymes are composed of proteins. (Proteins are chains of amino acids; see The Chemical Basis of Life.) When an enzyme functions, a key portion of the enzyme, called the active site, interacts with the substrate. The active site closely matches the molecular configuration of the substrate. After this interaction has taken place, a change in shape in the active site places a physical stress on the substrate. This physical stress aids the alteration of the substrate and produces the end products. During the time the active site is associated with the substrate, the combination is referred to as the enzyme-substrate complex. After the enzyme has performed its work, the product or products are released from the enzyme’s active site. The enzyme is then free to function in another chemical reaction.
Enzyme-catalyzed reactions occur extremely fast. They happen about a million times faster than uncatalyzed reactions. With some exceptions, the names of enzymes end in “–ase.” For example, the enzyme that breaks down hydrogen peroxide to water and hydrogen is catalase. Other enzymes include amylase, hydrolase, peptidase, and kinase.
The rate of an enzyme-catalyzed reaction depends on a number of factors, such as the concentration of the substrate, the acidity and temperature of the environment, and the presence of other chemicals. At higher temperatures, enzyme reactions occur more rapidly, but only up to a point. Because enzymes are proteins, excessive amounts of heat can change their structures, rendering them inactive. An enzyme altered by heat is said to be denatured.
Enzymes work together in metabolic pathways. A metabolic pathway is a sequence of chemical reactions occurring in a cell. A single enzyme-catalyzed reaction may be one of multiple reactions in a metabolic pathway. Metabolic pathways may be of two general types: catabolic and anabolic. Catabolic pathways involve the breakdown or digestion of large, complex molecules. The general term for this process is catabolism. Anabolic pathways involve the synthesis of large molecules, generally by joining smaller molecules together. The general term for this process is anabolism.
Many enzymes are assisted by chemical substances called cofactors. Cofactors may be ions or molecules associated with an enzyme and are required in order for a chemical reaction to take place. Ions that might operate as cofactors include those of iron, manganese, and zinc. Organic molecules acting as cofactors are referred to as coenzymes.
Adenosine Triphosphate (ATP)
The chemical substance that serves as the currency of energy in a cell is adenosine triphosphate (ATP). ATP is referred to as currency because it can be “spent” in order to make chemical reactions occur. The more energy required for a chemical reaction, the more ATP molecules must be spent.
Virtually all forms of life use ATP, a nearly universal molecule of energy transfer. The energy released during catabolic reactions is stored in ATP molecules. In addition, the energy trapped in anabolic reactions (such as photosynthesis) is trapped in ATP molecules.
An ATP molecule consists of three parts. One part is a double ring of carbon and nitrogen atoms called adenine. Attached to the adenine molecule is a small five-carbon carbohydrate called ribose. Attached to the ribose molecule are three phosphate units linked together by covalent bonds.
Adenosine Triphosphate Structure
The covalent bonds that unite the phosphate units in ATP are high-energy bonds. When an ATP molecule is broken down by an enzyme, the third (terminal) phosphate unit is released as a phosphate group, which is an ion. When this happens, approximately 7.3 kilocalories of energy are released. (A kilocalorie equals 1,000 calories.) This energy is made available to do the work of the cell.
The adenosine triphosphatase enzyme accomplishes the breakdown of an ATP molecule. The products of ATP breakdown are adenosine diphosphate (ADP) and a phosphate ion. Adenosine diphosphate and the phosphate ion can be reconstituted to form ATP, much like a battery can be recharged. To accomplish this, synthesis energy must be available. This energy can be made available in the cell through two extremely important processes: photosynthesis.
ATP Production
ATP is generated from ADP and phosphate ions by a complex set of processes occurring in the cell. These processes depend on the activities of a special group of coenzymes. Three important coenzymes are nicotinamide adenine dinucleotide (NAD), nicotinamide adenine dinucleotide phosphate (NADP), and Flavin adenine dinucleotide (FAD).
NAD and NADP are structurally similar to ATP. Both molecules have a nitrogen-containing ring called nicotinic acid, which is the chemically active part of the coenzymes. In FAD, the chemically active portion is the Flavin group. The vitamin riboflavin is used in the body to produce this Flavin group.
All coenzymes perform essentially the same work. During the chemical reactions of metabolism, coenzymes accept electrons and pass them on to other coenzymes or other molecules. The removal of electrons or protons from a coenzyme is oxidation. The addition of electrons to a molecule is reduction. Therefore, the chemical reactions performed by coenzymes are called oxidation-reduction reactions.
The oxidation-reduction reactions performed by the coenzymes and other molecules are essential to the energy metabolism of the cell. Other molecules participating in this energy reaction are called cytochromes. Together with the coenzymes, cytochromes accept and release electrons in a system called the electron transport system. The passage of energy-rich electrons among cytochromes and coenzymes drains the energy from the electrons to form ATP from ADP and phosphate ions.
The actual formation of ATP molecules requires a complex process called chemiosmosis. Chemiosmosis involves the creation of a steep proton (hydrogen ion) gradient. This gradient occurs between the membrane-bound compartments of the mitochondria of all cells and the chloroplasts of plant cells. A gradient is formed when large numbers of protons (hydrogen ions) are pumped into the membrane-bound compartments of the mitochondria. The protons build up dramatically within the compartment, finally reaching an enormous number. The energy released from the electrons during the electron transport system pumps the protons.
After large numbers of protons have gathered within the compartments of mitochondria and chloroplasts, they suddenly reverse their directions and escape back across the membranes and out of the compartments. The escaping protons release their energy in this motion. This energy is used by enzymes to unite ADP with phosphate ions to form ATP. The energy is trapped in the high-energy bond of ATP by this process, and the ATP molecules are made available to perform cell work. The movement of protons is chemiosmosis because it is a movement of chemicals (in this case, protons) across a semipermeable membrane. Because chemiosmosis occurs in mitochondria and chloroplasts, these organelles play an essential role in the cell’s energy metabolism. Photosynthesis explains how energy is trapped in the chloroplasts in plants, while Cellular Respiration explains how energy is released in the mitochondria of plant and animal cells.
