Nurse in Romeo and Juliet Essay Example For Students

Nurse in Romeo and Juliet Essay I am doing an essay about the Nurse in Romeo and Juliet. I will be looking at her character functions in the play, with the language and her impact of her in the play. The Nurse is employed by the Capulet family since the birth of Juliet, and the Juliets upbringing has been left entirely in her hands. The Nurse has a lot of affection for Juliet. She plays more of a mother figure to Juliet than her natural mother does. She provides entertainment by making jokes and bawdy comments. She also relieves the tragedy with her humour in the play. The nurse is an imperative character in the play because Shakespeare uses her to moves the plot forward. She is like a messenger informing Romeo and Juliet of the news and keeps the story going. Shakespeare also uses her to bring humour in the play which contrasts with the tragedy waiting to happen in the end of the play. In the play she is described as being as a capacious lady, she is written to wear a flowing dress. Romeo pretends that she is a ship and that her headscarf is a sail, A sail, A sail. From the way she looks, moves and wares bring humour in to the play. She audience laugh at her and from the Act 2 Scene 4 we can expect that she will be bringing humour in the play. All of the absurdity that she brings contrasts with the Tragedy of Rome and Juliet. She also heightens the problem or the tragedy and raises even more tension there is. The Nurse is very talkative, she loves to make speeches and talk about the past The Nurse frequently tells stories and is reminiscent about her past. E.g. She often talks about her daughter Susan, who became deceased when she was only months old. Susan and she- God rest all Christian souls- were of an age. This all make Lady Capulet and Juliet infuriated towards her. She often does not think before speaking, she frequently talks about sex to Juliet and says that marriage is not about love, but it is about sex. Yea, quoth he, fallst upon thy face? Thou wilt fall backward when thou comest to age wilt thou not, Jule? It stinted and said, Ay. She uses a lot of rude and sexual language in the play. She also recall what her husband said to her daughter dost thou fall upon thy face? Thou will fall backwards when thou hast move wit She tell Juliet another vulgar stories, which contrasts with the more noble language of Lady Capulet .She talks about sex in the presence of Lady Capulet, which is not very appropriate as she is a high status women and she is married, so when the Nurse talks about marriage being just about sex, Lady Capulet may feel uncomfortable. These types of characteristics irritate characters such as Lady Capulet but keep the audience humoured and entertained. This shows us that she is really close to Juliet in person closer than her own mother. The Nurse is totally devoted to Juliet and is also loyal towards her. Although she is thoughtless at times, her intentions are always good. Even when talking about uncomfortable issues such as sex to Juliet, she is only trying to warn Juliet about life from her experience, it might have been her own marriage which was based on sex. The nurse doesnt understand that times and people have changed. This shows the Nurses ignorance, as she is not well educated and not very intelligent The relationship of the Nurse and Juliet is more like a mother and daughter relationship where as lady Capulet and Juliet isnt. The Nurse takes care of Juliet and is very protective of Juliet. She tells Romeo to not mistreat Juliet But first let me tell ye, if ye should lead her in a fools paradise as they say it were a very gloss kind of behaviour. When Juliet speaks to her mother she speaks very formally, calling her madam. The conversation is stilted and proper, whereas with the Nurse she talks very openly. The Nurse uses many different terms when she is referring to Juliet, What, Lamb? What Ladybird? That is another sign of a close bond. The language in which they use to communicate is far less formal than that of the language with Lady Capulet. There seems to be a relaxed atmosphere around them. She is also a confidante towards Juliet, Juliet can tell her secrets and personal things to the Nurse. There relationship is like a relationship between two sisters and also a relationship between a mother and her daughter. This bond has been developed because the Nurse has looked after Juliet ever since she was a child and has treated as a daughter, as she has been wet Nurse for Juliet. As they spend so much time together, they feel they can trust each other and confide in one another. Lady Capulet relationship with Juliet is complete different, she doesnt fell comfortable being alone with Juliet Nurse, come back again, have rememberd me, thous hear our counsel The Lady wishes to discuss things with Juliet, but finds it uncomfortable. She calls the Nurse back immediately. She is seen as a trusted family servant to the Lord Capulet in Verona. Lady Capulet cant even talk to Juliet in private she need the nurse with her. This shows us that Lady Capulet is doesnt had close relationship with her own daughter while the Nurse does. We also see that Nurse tring to protect Juliet from her father, Lord Caplet when Capulet threatens and insults Juliet for refusing to marry Paris, the Nurse tries to intervene. She says Christmas Carol EssayNurse realises the depth of Juliet feelings for Romeo Ill to my wedding-bed And death, not Romeo, take my maidenhead Through the impact of these lines, which say that, not Romeo, will take her maidenhead but it will be death. At this point the Nurse shows sympathy and goes to fetch Romeo from the Lawrence cell, Ill find Romeo and Juliet tell her to gives her a ring to give to Romeo. Here the Nurse is also used as a messenger from Juliet to send Romeo a ring and tell him to come back to Juliet. The nurse does stand up for Juliet in Act 3 scene 5 against Juliets father violent rage against Juliet. The nurse was the only person that Juliet could turn to for help and comfort. At act 3 scene 5 Juliet gets threatened to marry Paris and she need the Nurse to help her to persuade her parents. She is in an impossible situation, she is already married to Romeo and the Nurse knows that. After all the outburst of Juliets parents the nurse advice Juliet to marry Paris, Romeo is banished hes as good as dead, disclout. From this point Juliet turns against the Nurse from this point she changes. When the Nurse confirms what she really thinks, that Juliet should marry Paris, Juliet says Amen I agree. But she doesnt mean it, she turns against the Nurse, she has changed and has her own mind. The nurse is no longer the person to whom Juliet can turn to. Juliet is angry and let down by the Nurse. Thou and my bossom henceforth shall be twain Now see will ask friar to know his remedy she will go to Friar Lawrence for help now. The nurse was being realistic when she was telling Juliet to marry Romeo which contrasted with Juliet romantic vision of her love. I think the Nurse still has Juliets best interest at heart and has not betrayed in any way. I feel the only reason the Nurse is telling Juliet to wed Paris as opposed to Romeo is because then she will still keep a good relationship with the Capulet family and so she doesnt end up on the streets, with no money and not a healthy life. As Romeo is banished, he cannot provide a good home and family for Juliet while Paris can and Juliet does not break her bonds with her family. For all her upbringing of Juliet, she is unable to understand her true feelings and fails to read her intentions when she apparently accepts Paris. At this point the audience would be shocked from what the Nurse has advised Juliet to do and would feel angry toward The Nurse. But as wee see the Nurse reaction towards the death of Juliet after drinking the potion we see that she really does care for Juliet. At act 4 Scene 5 we see .The nurse at Juliet chamber try to wake Juliet up for the wedding. She was the first person to find out that she was dead because she has a close relationship with Juliet and familiar intimate relationship When the nurse find out that Juliet is dead she is in horror Shes dead, deceased, shes dead Here Shakespeare uses repetition shes dead. He also uses the hard d sound alliteration, all this language get the horror impact for that scene. All this shows us the Nurse really cares about Juliet; she is like her own daughter. Its a very dramatic moment, she is distressed. In the play she would be in panic and it all shows us that she really cares about Juliet. On the other had her mothers reaction to Juliets death is completely different, she just thinks about herself. O me, O me, my child, my only life She is upset but Shakespeare uses interesting word to describe that, which implies that she is thinking about herself, me my. She only uses o my child o my life she just cares about herself. The father of Juliet has a deep regret over the death of Juliet, Shakespeare uses poetic language to describe the regret over the death, Death lies on her like an like an untimely frost Here Shakespeare uses simile to describe the death, he uses natural images which are very beautiful; Upon the sweetest flower of all the field. Here we have very beautiful images while the situation is very horrible. Shakespeare also uses gentle, soft sound images sweetest, he also uses alliteration flower field In line 85- 91 Shakespeare compares what the day would have been like, the sorrow of the death of Juliet that make the family change. That is the last scene in which we see the Nurse. Throughout the play, she appears, however when she loses Juliets trust, she is lost from the play. The Nurse plays a critical role in Romeo and Juliet. Without her, the play would be less entertaining as she adds humour to the play, but also makes the sad moment even more depressing as when Juliet dies, we feel sorry for the Nurse the most as she has brought her up from when she was born and she has to witness her tragic death, which she may feel partly responsible for, as she advised Juliet to forget about Romeo and wed Paris. The plot could not have been developed and the story could not have been facilitated if it was not for the essential character of the Nurse!

The Reasons For The Fall Of Socialism/Communism And The Troubles Essay

The Reasons for the fall of Socialism/Communism and the Troubles of Starting the New Democratic System in the Russian Federation "Let's not talk about Communism. Communism was just an idea, just pie in the sky." Boris Yeltsin (b. 1931), Russian politician, president. Remark during a visit to the U.S. Quoted in: Independent (London, 13 Sept. 1989). The fall of the Communist regime in the Soviet Union was more than a political event. The powerful bond between economics and politics that was the integral characteristic of the state socialist system created a situation that was unique for the successor states of the Soviet Union. The Communist regime was so ingrain in every aspect of Soviet life that the Russian people were left with little democratic tradition. Russia faces the seemingly impracticable task of economic liberalization and democratization. This is combined with the fact that the new administration must address human rights issues, such as living conditions and the supply of staple goods in this new form of administration makes the prospect of a full democratic switch seemingly impossible. To fully understand the scope of the transference of governing power in the Russian Federation, one must first look at the old Socialist/Communist regime, to see the circumstances under which it fell gives a good view of why this transference is almost impossible. In the beginning Communism seemed to the people of Russia as a utopian ideal. The promise of the elimination of classes, of guaranteed employment , "The creation of a comprehensive social security and welfare system for all citizens that would end the misery of workers once and for all." Lenin's own interpretation of the Marxian critique was that to achieve Communism there would first have to be a socialist dictatorship to first suppress any dissent or protest. Through coercive tactics this new government seized power and in 1917 Lenin came to power. Under his "rule" the Soviet Union underwent radical changes in it's economic doctrines adopting a mixed economy which was termed the New Economic Policy also referred to as NEP, this economy called for some private ownership of the means of production, but the majority of industry was made property of the people, which meant the majority of the means of production was controlled by the government. Lenin's government made many achievements. It ended a long civil war against the remnants of the old Czarist military system and established institutions in government. During this period, and in fact throughout the majority of the Communist rule, censorship and the subordination of interest groups such as trade unions was imposed to stop dissension and increase conformity to the new governments policies. Lenin died in 1924, and was quickly followed by Joseph Stalin as head of the Soviet Communist Party, the oppressive reforms started by Lenin were continued and at length became completely totalitarian. Stalin became the most powerful man in Russia. He controlled to bulk of all the political power and with that he started a ruthless campaign of removing all opposition to the Communist rule. During this period called the "Great Purge" Stalin systemically executed anyone who stood in his path. Millions of people were arrested and either harassed or killed. The economic status of the Soviet Union was yet again changed and the entire system became controlled by the government. All private ownership ended. A mass program of industrialization was commenced, and the strength of the Soviet Military was substantially increased. The citizens during this period endured great hardship. Agricultural production output diminished resulting in food shortages, these shortages were enha! nce by the mass exportation of food, this was done to pay for industrial imports. Stalin also put the production of what he called production goods such as manufacturing machinery over basic consumer goods such as clothes and other staples. During this period the Second World War broke out and drained most of what was left of the already impoverished state. Yet after the war national unity was strengthened as well is the Soviet military machine. The Soviet Union became a super power, the U.S. being the only country more powerful than it. After the death of Stalin in 1953 Nikita Khrushchev became First Secretary of the Communist party. Stalin's death marked the end of supreme power for the head of the party, and Khrushchev condemned Stalin's actions as unnecessary and harmful to the process of moving the Socialist government to it's goal of pure Communism. During this period the public was given a say in the government, albeit an extremely minor one, and the judicial system eased it's aggressiveness allowing a defendant a better chance of defending themselves. Khrushchev concerned himself with

Using a ChSpe Essay Sample For Your Own Essay

Using a ChSpe Essay Sample For Your Own EssayWhen writing your very own personal essay, you can use a ChSpe essay sample to help hone your skills before you start submitting the work. This can help you get things like sentences that make sense and read naturally so that the reader is more inclined to want to continue reading.As mentioned above, this type of essay is written in two sections: the first part is used to help you brainstorm on different things you want to say. The second part is a compile and analyze of what you have written so far. These two sections will require different types of essay writing skills and should be tackled in a separate part of the assignment.Some of the easier things that can be done from ChSpe prompts are phrasing questions so that it will look like you are doing research. For example, in your essay you might ask the reader, 'Why is college so expensive?'With that in mind, you can alter the word usage slightly so that you are able to create a sound ef fect with the sentence. This is just one example of how you can use this type of essay to personalize the topic of your own research.Another way to get some ideas for essay topics is to ask yourself, 'What do I know about this topic?' You might answer this question by answering, 'I know a lot about my mother's maiden name.' As an example, your mom was named Helen Smith but she changed her name to the famous Helen Keller.Many times you can get a lot of ideas using these types of prompts. In addition, if you are having trouble coming up with a topic for your assignment then you can send an e-mail to ChSpe. They will be happy to assist you in coming up with the right topic for you.If you do get stuck in the middle of an essay, be sure to discuss your writer's block with a friend. You might find that talking to someone else can help you get back on track.ChSpe essay sample prompts are great for helping you determine which type of essay you are interested in writing. You should also take advantage of the various forms that the ChSpe community offers when you are writing your own. This will allow you to come up with a topic that you enjoy as well as one that is not too difficult for you to write.

President Roosevelt Essays - Freemen Of The City Of London

President Roosevelt Essays - Freemen Of The City Of London President Roosevelt Just after war broke out in Europe, President Roosevelt hurriedly called his cabinet and military advisors together. There it was agreed that the United states stay neutral in these affairs. One of the reasons given was that unless America was directly threatened they had no reason to be involved. This reason was a valid one because it was the American policy to stay neutral in any affairs not having to with them unless American soil was threatened directly. Thus the provisional neutrality act passed the senate by seventy-nine votes to two in 1935. On August 31, Roosevelt signed it into law. In 1936 the law was renewed, and in 1937 a comprehensive and permanent neutrality act was passed (Overy 259).

Mobile Pet Grooming (Truck Pet Grooming) Research Paper

Mobile Pet Grooming (Truck Pet Grooming) - Research Paper Example s of services that will entail forging a closer bond between the owner and the pet, general cleaning of the dog, reduction of parasite infestation load, monitoring the health of the dog through physical examinations of swellings, cuts, scratches, cuts, changes in temperament as well as lameness. Our grooming professionals will also conduct a health examination using sophisticated machines with an intension of decreasing chances of other health problems such as scratches, thrush and other skin related condition. Our services will cover a large area of the city with our professionals performing their best to ensure the needs of the many customers are met. Our employees will utilize the various tools owned by the firm such as curry brush, clippers, shedding blade, stripping comb, slicker brushes, rakes, and stand dryers to attend to the pets in a professional manner. Duraz mobile pet grooming business will be headquartered in Los Angeles in the state of California and will extend to other places in the state after assessing the need. The business will be started in California as a result of many people in the town owning pets such as dogs and cats. California is one of the most populated states in the United States of America and has people of all of all the classes (CHANG, 1750). Major cities in California with highest number of people who owns dog include San Francisco, Rodeo drive, Hollywood, Los Angeles and San Diego (Packard, 63). The large number of people with a high percentage of them having pets will offer ready market for the mobile grooming services. The number of mobile pet grooming services is less compared to over a hundred thousand pets available in the state. Most people in California have pets especially dogs. The dog owners have a habit that often seems perplexing; they seem to be so much obsessed with dogs (BaÇ §cigil et al, 1350). Around three quarters of dog owners in California consider their pet as a family member and will pay anything to

The impact of social media on brand image of UK coffee shops Dissertation

The impact of social media on brand image of UK coffee shops - Dissertation Example The main objective of this dissertation has been to identify the impact of the social media sites on the brand image of coffee shops in the UK for which Starbucks has been considered as the sample brand. In order to attain the objective, this dissertation has taken into consideration a mixed approach. Furthermore, the sample size for the project is 200 respondents who were supposed to respond to online survey. Questionnaire was also prepared comprising of close-ended questions. In this regard, it has been identified that social media sites imposes a significant impact on the creation of brand image of Starbucks. Table of Contents 1 Abstract 2 Chapter 1: Introduction 5 1.1.Background of the Study 5 1.2. Scope and Objective of the Study 8 1.3 Methodological Overview 11 1.4 Structure of the Project 12 Chapter 2: Literature Review 14 2.1 The Growing Significance of Social Media in the Business Environment of UK (Coffee Retailing) 14 2.2 Contribution of Social Media in Developing Brand Im age 16 2.3 Influencing Factors Causing Impact on Inclusion of Social Media 20 2.4. Opportunity and Risks of Social Media Inclusion 25 2.5 Organisational Strategies Generally Adopted By UK Coffee Shops to Use Social Media 30 2.6. Research Gap 33 Chapter 3: Research Methodology 35 3.1 Overview 35 3.2 Research Philosophy 36 3.3 Research Design and Approach 37 3.4. Data Collection 40 3.5 Data Analysis 41 3.6 Ethical Considerations and Research Limitations 43 3.7 Expected Results 45 Chapter 4: Results and Analysis 47 4.1 Overview 47 4.2 Findings 47 4.3 Evaluation 68 Chapter Five: Conclusion and Recommendations 77 5.1 Key Findings 77 5.2 Recommendations 79 5.3 Further Research 82 References 84 Appendix A 97 Questionnaire 97 Chapter 1: Introduction 1.1. Background of the Study Social media has been successful at rediscovering the association between companies, employees, suppliers as well as regulators, minimising the implementation of methods that were generally identified as quite time-c onsuming in the traditional era concerning public relations. Most of the companies are making use of the social media so that their efficiencies can be enhanced in respect to the supply chain (Lew & Fung, 2010). In the similar context, others are making use of the social media so that they can create innovative business models and develop relationships with the customers, employees, investors as well as other interested stakeholders gaining the identification of a socially responsible corporate entity. A handful of the companies are making use of the social media sites so that they can boost the morale of the employees and hence enhance efficiency in terms of communication within the organisational setting. The companies striving to strengthen their brand, customer loyalty as well as increase the market share are also making use of the social media sites (Insead, 2012). Although, social media users are basically found to belong from the young age group of the society, an increasing number of middle aged users, especially those possessing a higher level of discretionary income. It has been noted that nearly 67% of the users of the social media believe that the information rendered online imposes a significant impact on their purchasing decision. In the recent phenomenon, it has further been observed that this trend is likely to continue, majorly owing to the underlying fact that advances in technology continue to increase the impact of social media. This trend has permitted the consumers to

Role of ATP in Supporting Energy to the Body Essay Example for Free

Role of ATP in Supporting Energy to the Body Essay When food is ingested, it is broken down into components and utilized in a specific manner in three major cellular pathways to provide energy for the cells and the body.   Ultimately, these pathways involve the breakdown and utilization of food, the utilization of O2 and the production of CO2, the generation and regeneration of ATP and the production of water.   Therefore, these processes involve respiration as well as the breakdown and utilization of food and oxygen. Three major pathways are involved:   glycolysis which takes place in the cellular cytoplasm and breaks down glycogen and glucose from food, the Krebs Cycle which occurs in the mitochondrion and oxidative phosphorylation which occurs in the mitochondrion.   Ã‚  Ã‚   These three pathways occur in two cellular locations.   Glycolysis takes place in the cytoplasm and The Krebs Cycle and oxidative phosphorylation take place in the mitochondria.   During these three pathways, there is a utilization and production of ATP that biochemists follow closely.   It results in the net production of 36 molecules of ATP.   Ã‚  Ã‚  Ã‚   To understand the entire process that illustrates how food is broken down and utilized in the body, it is instructive to follow a bolus, that is, food consumed, chewed and swallowed.   Each step involves some aspect of digestion that breaks down complex sugar and protein molecules into smaller units.   Proteins are broken down into peptides and amino acids while starches and other complex sugars are broken down into glucose. The glucose undergoes glycolysis in the cellular cytoplasm beginning with the enzyme hexokinase, and the entire process of glycolysis is controlled by the rate limiting enzyme phosphofructokinase (PFK).   Kinase enzymes (enzymes that break down ATP) are common all along the three pathways involved, glycolysis, the Krebs Cycle (also called the Citric Acid Cycle and the Tricaroxylic Acid Cycle) and phosphorylative oxidation.   Kinases are enzymes that break down or utilized ATP, ADP and AMP as their substrate or one of their substrates.   Ã‚  Ã‚  Ã‚   Fiske and Subbarow discovered and characterized ATP in 1929.   At that time, the work of some demonstrated that the breakdown of ATP provided energy for muscle contraction, but other studies demonstrated that there was ATP synthesis during glycolysis and during electron transport.   Although ATP is made throughout the cell, the cellular location of ATP synthesis varies with the biochemical pathways associated with ATP synthesis.    Although one common pathway of ATP synthesis and breakdown is associated with the adenylate kinase reaction that forms two ADP molecules from ATP and AMP, studies in the late 1920s and beyond demonstrated that ATP synthesis was also associated with glycolysis and during electron transport.   In 1949, Kennedy and Lehninger demonstrated that ATP synthesis and the citric acid cycle occur in the mitochondria.   We now recognize that ATP synthesis and breakdown can be associated with specific biochemical pathways in the cell cytoplasm and in the mitochondria.    Some enzymes are sensitive to the ratio of ATP to AMP and to the presence of ADP.   This realization led to the concept of the energy charge, the relative concentration of ATP to ADP to AMP in the cell.   An energy charge of 1.0 represents all ATP, and energy charge of 0 represents all AMP and an energy charge of 0.5 represents all ADP or equal amounts of ATP and AMP or some combination of the two.   These ratios, and thus the energy charge are important to the cell because many cellular enzymes such as PFK are sensitive to and regulated by the relative amounts of the adenine nucleotides, ATP, ADP and AMP. Glycolysis   Ã‚  Ã‚  Ã‚   Glycolysis, also referred to as the Embden-Meryhof-Parnas pathway (figure 1), is essentially the breakdown of glucose in the cytoplasm of the cell.   The glycolytic process can begin with glucose or glycogen.   During the process, glycolysis generates the high energy compounds ATP and NADH that serve as the energy sources in the cell.   Among the many cellular roles for glycolysis, it serves three central cellular functions.   First, it generates high energy molecules such as ATP and NADH. It also produces pyruvate for the Krebs cycle and a variety of three and six carbon compounds involved in the intermediary metabolism of the cell.   The rate limiting enzyme for glycolysis, that is, the key enzyme that controls the glycolytic pathway, is phosphofructokinase (PFK).   PFK is feedback inhibited by high levels of ATP which acts by lowering the affinity of the substrate F6P for PFK.   AMP can reverse the inhibitory effect of ATP rendering PFK, and thus the control of glycolysis very sensitive to the ratio of ATP/AMP in the cytoplasm.   Ã‚  Ã‚  Ã‚   The final product arising from glycolysis depends on the cellular conditions.   Whereas glycolysis begins with glucose or glycogen, it ends with the production two molecules of the three carbon compound pyruvate.   Under anaerobic conditions, pyruvate is reduced to form lactic acid or ethanol and under aerobic conditions pyruvate loses CO2 and forms the product acetyl-coenzyme A as a result of oxidation of pyruvate to carbon dioxide and water in the citric acid cycle within the mitochrondia.   Glycolysis occurs in the cellular cytoplasm and the Krebs Cycle and oxidative phosphorylation occur in the mitochondria.   Ã‚  Ã‚  Ã‚   Glycolysis results in the formation of fructose from glucose and the formation of glyceraldehyde 3-phosphate, 3-phosphoglycerate and compounds along the pathway on the way to splitting the resulting 6-carbon compound into two three carbon units of pyruvate.   In the process, NAD+ serves as a hydrogen carrier and is reduced to NADH, the oxidized form of NAD+. In the cell, the oxidation of aldehyde to carboxylic acid is very complex and strongly exergonic and is generally coupled to ATP synthesis.   Glucose goes to Glu-6-P to Fructose with the breakdown of two ATP molecules.   Fructose gives rise to glyceraldehyde-3-phosphate which is ultimately splite in a complex reaction chain to phosphoglycerate, phosphoenolpyruvate which is finally split into two molecules of pyruvate by pyruvate and the regeneration of the two ATP molecules previously utilized. Glycolysis Figure 1. Embden-Meryhof-Parnas pathway, also known as glycolysis.   Reproduced from Michael W. King, Wednesday, 22-Mar-2006. The Citric Acid Cycle   Ã‚  Ã‚  Ã‚   The Citric Acid Cycle (Figure 2) is the most complex of the three components associated with carbohydrate metabolism and the consumption of food.   It involves the following eight enzymes and the components they use as substrate:   Citrate Synthase, Aconitase, Isocitrate Dehydrogense, alpha-ketoglutarate Dehydrogenase, Succinyl-CoA Synthetase, Succinate Dehydrogenase, Fumarase, Malate Dehydrogenase.   The generation of acetyl-CoA from carbohydrates is a major control point of the Krebs cycle.   Therefore, glycolysis and the rate limiting enzyme of glycolysis, PFK, play a role in the control of the Krebs cycle.   The oxidation of an acetyl group is a difficult chemical process and may be the reason that nature developed the Tricarboxylic Acid Cycle (TCAC), also known as the Citric Acid Cycle and the Krebs Cycle. The Krebs cycle begins when the products of glycolysis leave the cytoplasm (cytosol) and enter the mitochondria.   Once glycogen or glucose have been broken down into two three carbon units of pyruvate, the pyruvate can be further broken down into a high energy compound called acetyl-CoA resulting in the production of CO2 and water.   Acetyl-CoA combines with oxaloacetate (also spelled oxalacetate) to form the 6 carbon compound citrate.   From this condensation reaction, a complex array of biochemical reactions take place that involve various molecular transformations such as isomerizations and molecular rearrangements. These various steps result in transformations from the 6-carbon condensation that gave rise to citrate and subsequent 6-carbon units of cis-aconitate, isocitrate to a five carbon unit of alpha-ketoglutarate to the four carbon units of succinate, fumarate, malate and oxaloacetate which, once regenerated is available to combine with another high energy acetyl-CoA and form another unit of citrate under the influence of the enzyme citrate synthetase.   After citrate is formed, two carbon atoms are removed as CO2 as the various TCAC intermediates are formed leading to the regeneration of the 4-carbon oxaloacetate. There are several oxidation steps on the way to the reformation of oxaloacetate.   Each step feeds reducing agents, either NADH or FADH, into the cycle on the way to regenerating oxaloacetate from citrate.   The reducing agents (or reducing equivalents) remove hydrogen from the enzyme substrates.   So, the reducing agents serve as a pool of hydrogen carriers and allow for the further synthesis of ATP during electron transport.   The TCAC results in the production of 2 ATP molecules, 10 carrier molecules and CO2 from each molecule of glucose. Glycolysis and the Krebs Cycle Figure 2. Glycolysis and the Krebs Tricarboxylic Acid Cycle (TCAC).   Reproduced  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   from David R. Caprette, 2005. Electron Transport   Ã‚  Ã‚  Ã‚   The complex molecules that were reduced during the Krebs Cycle are re-oxidized by means of the electron transport system. (Figure 3)   Although TCAC results in the production of 2 ATP molecules from each molecule of glucose, electron transport gives rise to 34 ATP molecules and water from the carrier molecules.   Therefore, the majority of the ATP in the cell must be produced in the mitochondria.   The re-oxidation of reduced NADH and FADH2 by O2 involves a sequence of electron carriers in what has become known as the electron transport chain.   It ultimately results in the generation of three molecules of ATP from ADP and inorganic phosphate for every oxygen molecule involved. This process is called oxidative phosphorylation and is the principal source of usable energy (in the form of ATP) in the cell.   It is provided by the breakdown of both carbohydrates and fats.   In the process, reduced NADH transfers a hydrogen atom plus two electrons (a hydride ion and H-).   Two complex molecules, NAD+ and FAD+, serve as the pool of hydrogen carriers and thus act reducing agents in the mitochondria; NAD+ is reduced to NADH and FAD is reduced to FADH2.   These compounds serve as electron carriers because their oxidation or reduction, the transfer of H+ (a proton), is accompanied by one or two of the electrons. The electrons donated from NADH or FADH2, upon entering this complex, travel from one carrier to the next, with each carrier being a somewhat more powerful oxidant than the previous one.   The hydrogen donated by the reducing agents combines with O2 such that with each molecule of O2 combines with 4 H+ to form water.   Therefore, two molecules of NADH must pass four electrons down the electron transport chain for each reduced oxygen molecule (O2). The chemical structures of the components of the electron transport chain fall into several distinct classes.   Most are proteins that contain special coenzymes called prosthetic groups.   Although they differ in chemical structure, a major difference between NADH and FADH2 is that NADH difuses freely between the dehydrogenases transfer hydrogen to it whereas FAD+ and FADH2 do not.   Another class of electron carriers in the mitochondrial membranes is iron-sulfur [Fe-S] clusters that are bound to proteins and release Fe3+ or Fe2+ plus H2S when acidified.   All of the carriers only appear to carry one electron at a time.   Ã‚  Ã‚  Ã‚   Ubiquinone or Coenzyme Q is a third hydrogen carrier localized in the mitochondrial membranes.   It is a common electron carrier that collects electrons from three or more points of input along the electron transport chain and passes them to molecular oxygen.   Unlike the other mitochondrial electron carriers, ubiquinone is not uniquely associated with proteins.   The cytochromes are a final class of electron carrier localized in the mitochondrial membrane.   Cytochromes are small, chemically distinct proteins that contain heme.   Like the other electron transport agents, the cytochromes only carry a single electron.   Cytochromes pass electrons from cyt bcyt ccyt acyt a3O2 Electron Transport/Oxidative Phosphorylation Figure 3.   Electron Transport during Oxidative Phosphorylation.   Reproduced from M. W. King, 2001. Summary   Ã‚  Ã‚  Ã‚   The pathways discussed here involve food consumption and energy utilization arising from food consumption.   Once food is taken in and reaches the stomach, it enters the body and the cells of the body.   Before digestion, food consists of complex, long chain molecules that must be broken during digestion beginning in the mouth and continuing in the stomach.   Once digested food reaches the cells, long chain molecules such as starch and other complex carbohydrates are further broken down into glucose.   Glucose, a six carbon compound, undergoes the process of glycolysis in the cellular cytoplasm to become two three carbon units of pyruvate. Under anaerobic conditions, pyruvate goes to lactic acid or ethanol, but in the presence of oxygen, pyruvate breaks down into a two-carbon compound, Acetyl-CoA and enters the Krebs Cycle.   There, food can be used to form energy for the cell in the form of ATP.   In the mitochondria, 36 molecules of ATP are formed for each molecule of O2.   Two ATP molecules arise from the Krebs cycle and 34 molecules arise from electron transport for each molecule of oxygen.   Thus, food consumed and oxygen taken in combine to replenish the energy supplies in the body in the form of ATP. References Caprette, David R.   Substrate Oxidation:   Krebs Reactions.   Experimental Biosciences 31 May, 2005.   The Krebs Cycle:   http://www.ruf.rice.edu/~bioslabs/studies/mitochondria/mitokrebs.html, Thursday, 7 June 2007. King, Michael W. Digestion of Dietary Carbohydrates.   Wednesday, 22-Mar-2006 Glycolysis: http://web.indstate.edu/thcme/mwking/glycolysis.html, Thursday, 7 June 2007 King, Michael W. Principals of Reduction/Oxidation (Redox) Reactions. Friday, 30 Mar-2007.   Oxidative Phosphorylation:   http://web.indstate.edu/thcme/mwking/oxidative-phosphorylation.html, Thursday, 7 June 2007.