The Citric Acid Cycle/ Kerbs Cycle/ TCA The Citric acid cycle is important as anaerobic glycolysis can only harvest a fraction of the energy from glucose. In the citric acid cycle there is aerobic respiration of pyruvate from step ten in glycolysis to C02 and H2O. This oxidation of pyruvate can greater a higher yield of ATP. The citric acid cycle occurs in the mitochondria where ten ATP is produced. The main purpose of the citric acid cycle is to harvest electrons from the citric acid cycle and produce reduced compounds, then these reduced compounds are transported to the electron transport system and be used in the manufacturing of ATP. A unique feature of the citric acid cycle is that it is a common place where the macronutrients, carbohydrates, …show more content…
Therefore pyruvate must be oxidised to yield Acetyl-CoA and CO2 which is carried out by pyruvate dehydrogenase (PHD). This is a complex structure that consist of a cluster of enzymes found in the mitochondria of eukaryotic cells. This reaction is called the oxidative decarboxylation. It is an irreversible oxidative process. Here the carboxyl group is removed from the pyruvate as a molecule of C02 and the remaining two carbons are used to become the acetyl group in the Acetyl-CoA. Therefore pyruvate C3 is converted to acetate c2. In this reaction Coenzyme A is needed. NADH is also created in this reaction. The NADH gives a hydride ion to the respiratory chain. …show more content…
This reaction uses the enzyme aconitase. This is a reversible reaction. Iso- citrate is formed through the intermediate formation of cis-aconitate. Aconitase is an iron sulphur enzyme. In step three iso-citrate is oxidised to α-ketoglutarate and also CO2 is released. The enzyme which catalysis this reaction is iso- citrate dehydrogenase. It catalyses the oxidative decarboxylation of iso- citrate to create α-ketoglutarate. In this reaction a six carbon sugar is reduced to a five carbon sugar. In step four α-ketoglutarate is oxidised to Succlnyl-CoA. It is oxidation decarboxylation step. It is catalysed by the enzyme α- Ketoglutarate dehydrogenase complex. This reaction is identical to the pyruvate dehydrogenase reaction. A five carbon sugar is reduced to a four carbon sugar. In step five Succlnyl-CoA is converted into Succinate. There is a strong negative standard of free energy from the hydrolysis. In the next step the energy that is released in breaking this bond is used to drive the synthesis of phosphoanhydrice used to create GTP nad ATP. Succinate is created in this process. It is a reversible reaction catalysed by Succlnyl-CoA synthetase. In steps six to eight is all about the regenerating of