The Process of Glycolysis Essay

The krebs cycle is the second step in aerobic respiration of cells, which takes place in the matrix of the mitochondria of eukaryotic cells. This process is to oxidize pyruvate.

In contrast, there are four metabolic stages happened in cellular respiration, which are the glycolysis, the citric acid cycle, and the oxidative phosphorylation. Glycolysis occurs in the cytoplasm, in which catabolism is begun by breaking down glucose into two molecules of pyruvate. Two molecules of ATP are produced too. Some of they either enter the citric acid cycle (Krebs cycle) or the electron transport chain, or go into lactic acid cycle if there is not enough oxygen, which produces lactic acid. The citric acid cycle occurs in the mitochondrial matrix, which completes the breakdown of glucose by oxidizing a derivative of pyruvate into carbon dioxide. The citric acid cycle produced some more ATPs and other molecules called NADPH and FADPH. After this, electrons are passed to the electron transport chain through

This process does not require oxygen and is referred to as fermentation. This process partially breaks down carbohydrates and it obtains a small amount of energy, again in the form of ATP. Pyruvic acid has to be broken down in respiration when formed by breaking down of glucose molecules, this can't be done in the same way as in aerobic respiration. When anaerobic respiration is taking place carbon dioxide and ethanol is formed.

There are two types of cellular respiration, aerobic and anaerobic. Aerobic respiration occurs when there is oxygen present and in the mitochondria (in eukaryotic cells) and the cytoplasm (in prokaryotic cells). Aerobic respiration requires oxygen; it proceeds through the Krebs cycle. The Krebs cycle is a cycle of producing carbon dioxide and water as waste products, and converting ADP to thirty-four ATPs. Anaerobic respiration is known as a process called fermentation. It occurs in the cytoplasm and molecules do not enter the mitochondria for further breakdown. This process helps to produce alcohol in yeast and plants, and lactate in animals. Only two ATPs are produced through this process. In yeast fermentation is used to make beer, wine, and whiskey.

One of the most significant reactions in Glycolysis is reaction one which involves the phosphorylation of glucose to form glucose-6-phosphate. Through the transfer of the hydrolysis of ATP, this supplies energy for the reaction and makes it essentially irreversible, having a negative free energy change, which allows for a spontaneous reaction in cells. Although the preparatory phase is energy consuming and uses up 2 ATP, the pay off phase synthesizes 4 molecules of ATP, with the transfer of 4e- via 2 hydride ions to 2 molecules of NAD+. Therefore, a net gain of 2 ATP is achieved through the glycolytic pathway alone. Following the glycolytic pathway, due to the absence of oxygen, as oxygen cannot be supplied fast enough to undergo aerobic respiration, the athlete will instead, undergo lactic acid fermentation. Lactic acid fermentation involves pyruvate that is formed from the glycolytic pathway to be reduced to lactate, with the aid of the enzyme, lactate dehydrogenase, while the coenzyme Nicotinamide Adenine Dinucleotide (NADH) is oxidised to NAD+. The product NAD+ then re-enters the glycolytic pathway in order to produce 2 ATP. This process of lactic acid fermentation produces 2 ATP for each cycle, and thus, rapidly supplies the body with a small amount of energy. However, with the buildup of lactic acid in the body, the athlete will eventually encounter the feeling of discomfort as this accumulation of lactate causes the body to

Aerobic respiration happens only when oxygen is presented in the cell. Aerobic respiration starts with pyruvate crossing into the mitochondria. When it passes through, a Coenzyme A will attach to it producing Acetyl CoA, CO2, and NADH. Acetyl CoA will enter into the Krebs cycle. In the Krebs cycle Acetyl CoA will bound with Oxaloacetic Acid (OAA), a four carbon molecule, producing the six carbon molecule, Citric Acid. Citric Acid will reorganize into Isocitrate. This will lose a CO2 and make a NADH turning itself into alpha ketoglutarate, a five carbon molecule. Alpha ketoglutarate will turn into an unstable four carbon molecule, which attaches to CoA making succinyl CoA. During that process a CO2 and NADH is made. An ATP is made when CoA leaves and creates Succinate. This molecule is turned into Fumarate, creating two FADH2 in the process. Then Fumarate is turned into Malate then into OAA making two NADH. Only two ATP is produced in Krebs cycle but the resulting NADHs and FADH2s are passed through an electron transport chain and ATP synthase. When the molecules passes through that cycle a total of 28 ATP molecules are produced. In all aerobic respiration produces 32 ATP and waste products of H2O and

The citric acid cycle, also called the Krebs cycle or the tricarboxylic acid, TCA, cycle, a series of chemical reactions that generates energy from the oxidation of acetate into chemical energy and carbon dioxide in the form of ATP. It also provides NADH, which is a reducing agent that is very common in biochemical reactions. This cycle is constantly supplied with new carbon. This comes in from acetyl-CoA, which starts the entire process of the citric acid cycle. The first step of the citric acid cycle is the aldol condensation of oxaloacetate and acetyl-CoA and water with the enzyme citrate synthase in order to form citrate and CoA-SH. The next step is the dehydration of citrate with the enzyme aconitase in order to form cis-aconitate and water. Then comes the hydration of cis-Aconitate and water with the enzyme aconitase in order to form isocitrate. The next is the oxidation of isocitrate and NAD+ with the enzyme isocitrate dehydrogenase in order to form oxalosuccinate and NADH and H+. Then, there is the decarboxylation of oxalosuccinate with the enzyme isocitrate dehydrogenase in order to form alpha-ketoglutarate and carbon dioxide. Next, there is the oxidative decarboxylation of alpha-ketoglutarate and NAD+ and CoA-SH with the enzyme alpha-ketoglutarate dehydrogenase in order to form succinyl-CoA and NADH and H+ and carbon dioxide. The next step is the substrate-level phosphorylation of succinyl-CoA and GDP and Pi with the enzyme succinyl-CoA synthetase in order to form succinate and CoA-SH and GTP. Then, there is the oxidation of succinate and ubiquinone with the enzyme succinate dehydrogenase in order to form fumarate and ubiquinol. Next, is the hydration of fumarate and water with the enzyme fumarase in order to form L-malate. The final step is the oxidation of L-malate and NAD+ with the enzyme malate dehydrogenase in order to form oxaloacetate and NADH and H+. Two cycles are required for every single glucose molecule because two acetyl Co-A molecules

The acetyl group from pyruvate is oxidised in a series of nine reactions; the citric acid cycle. Also known as the Krebs cycle, it is the second stage of cellular respiration. Cellular respiration is a 3 stage process where organic fuel molecules are broken down, in the presence of oxygen, to harvest energy. These reactions occur in the mitochondrial matrix.

Glycolysis is followed by the Krebs cycle, however, this stage does require oxygen and takes place in the mitochondria. During the Krebs cycle, pyuvic acid is broken down into carbon dioxide in a series of energy-extracting reactions. This begins when pyruvic acid produced by glycolysis enters the mitochondria. As the cycle continues, citric acid is broken down into a 4-carbon molecule and more carbon dioxide is released. Then, high-energy electrons are passed to electron carriers and taken to the electron transport chain. All this produces 2 ATP, 6 NADH, 2 FADH, and 4 CO2 molecules.

2. (6 pts) Turn your head to the right. (Create a table* that describes which muscles move which bones across which joints under the control of which nerves)

Uniquely, glycolysis is both anaerobic and aerobic. The end product pyruvate, from glycolysis, is anabolized to lactic acid when there is a need for energy without an adequate supply of oxygen available. This last step or reaction enables glycolysis to continue producing ATP without the need for oxygen, which is why it is called the anaerobic energy system (Fink, 2009).

The Krebs cycle is a series of reactions which occur in the mitochondria and results in the formation of ATP and other molecules which undergo farther reactions to form more ATP. Cellular respiration can be divided into four sequences. The first sequence is glycolysis, its breaks down one molecule glucose into two molecules pyruyate. Transition takes place in the matrix of the mitochondria and it’s referred to the beginning of aerobic respiration. The process takes place if there is enough amounts of oxygen in the mitochondria. However if there is insufficient oxygen in the mitochondria it could result into fermentation. Transition Reactions take place in the pyruvate molecule. In transition reactions two hydrogen electrons and one carbon

aerobic respiration the Pyruvate enters the Citric acid cycle in which 6 CO2 (1 molecule

Mitochondrial respiration (aerobic metabolism) occurs in the mitochondria of the cells when the oxygen supply is sufficient to meet the oxygen demands (Smith, 2002).

Metabolism is defined the sum of all chemical reactions which occurs and are involved in sustaining life of a cell, and thus an organism. Metabolism is of the following two types: catabolism and anabolism. In catabolism, molecules break down producing energy