Zayra Mendivil
EXS-340
September 29, 2013
William Kuehl
Energy Transfer
Glycolysis is the metabolic pathway that takes glucose and breaks it down into pyruvate. This anaerobic cycle that can occur in the presence of oxygen or not. It is used to release high energy compounds of adenosine triphosphate, ATP. Glycolysis takes one glucose and results in two three carbon chains of pyruvate, along with a net total of two ATP released.
The Kreb, or Citric Acid, Cycle is series of chemical reactions used by aerobic organisms to generate energy following Glycolysis. The process between glycolysis and the start of the Kreb Cycle takes the pyruvate at the end of glycolysis, converts it to acetic acid by removing the C02 and then the acetic acid is combined with coenzyme A to form acetyl coenzyme A. From here the Acetyl CoA is converted to citric acid by removing CoA, hydrogen and electrons are released and then accepted by NAD+ and C02 removed resulting in the remaining structure recombining with CoA. The Kreb cycle involves citric acid being taken consumed and regenerated. Alongside, acetyl coenzyme A is consumed with water, NAD+ reduced to NADH and carbon dioxide produced. The end result of these two pathways is the production of thirty-six to thirty-eight usable ATP from the oxidation of nutrients.
Energy metabolism in the body is regulated by three classes of fuel molecules, carbohydrates, lipids, and proteins. Metabolic pathways are organized by chemical reactions through enzymes. Enzymes are crucial to metabolism because they allow steps to occur to get the wanted reactions. Enzymes help all steps to be quick and efficient.
The main chemical limiting factors of exercise is the inability to have an unlimited production of ATP in the body. While ATP production occurs through three metabolic pathways, eventually all paths become exhausted and the body no longer contains enough glycogen to continue or energy to create more ATP.
Throughout the metabolic cycles, oxygen plays one major role, a carrier. It helps in attachment of other compounds. Additionally, oxygen is needed to create ATP.
Amino acids release energy through hydrolysis catalyzed by amino acids that then enter the citric acid cycle in several different ways. These results in the formation of carbon dioxide and the release of hydrogen with electrons that then combine with oxygen to form water. This then releases energy. Some amino acids are converted to pyruvate or pyruvic acid, while others are converted into acetyl CoA.