Citric Acid Cycle Lab Report

The citric acid cycle is an amphibolic pathway. It utilises both anabolic and catabolic reactions; the first reaction of the cycle, in which oxaloacetate (a four carbon compound) condenses with acetate (a two carbon compound) to form citrate (a six carbon compound) is typically anabolic. The production of the isomeric isocitrate is simply intramolecular rearrangement. The subsequent two reactions are typically catabolic, producing succinate (a four carbon compound), which is then oxidised, forming fumarate (a four carbon compound). Water addition produces malate and then oxidised for regeneration of oxaloacetate. Thus the cycle can be seen to exhibit both anabolic and catabolic processes to form its intermediates.

An essential dissimilarity

between the actions of catabolism and anabolism here is the use of different coenzymes in their pathways. In catabolism, NAD+ is the oxidising agent which is reduced to form NADH, whereas in anabolism the coenzyme NADPH is the reducing agent and is oxidised to become NADP+.