Pyruvate and acetyl Coenzyme A form the most important intermediates in both anabolic and catabolic processes of metabolism. In metabolism, a number of enzymatic reactions which are organized in discrete pathways take place in living cells to transform substrates into their products through various chemical intermediates. Metabolism involves two processes, catabolism and anabolism. Catabolism is energy producing process in living cells while anabolism involves energy expenditure to produce new biomolecules. Pyruvate and acetyl Coenzyme A participate as intermediates in both anabolic and catabolic pathways (Berg, Tymoczko & Stryer, 2002).
Acetyl Coenzyme A and pyruvate take part in energy generating (catabolic) process in living cells. Catabolic processes serve to provide various intermediates which are broken down to yield ATP and NADPH which are energy molecules. Glucose, which is the main energy substrate, provides pyruvate and acetyl Coenzyme A as well as oxaloacetate (OAA) which are key intermediates in the tricarboxylic acid (TCA) cycle. The two intermediates feed into the TCA cycle in the mitochondrion for energy production (Berg, Tymoczko & Stryer, 2002).
While acetyl Coenzyme A and pyruvate feed into the TCA cycle for energy production, they are also recognized as important intermediates in anabolic processes. In anabolic metabolism, cellular energy in form of ATP is used in the production of acetylcholine and pyruvate in the process of glycolysis. Acetylcholine is also delivered through the process of beta-oxidation which involves the breakdown of fatty acids. Pyruvate is produced in the process of glycolysis from phosphoenolpyruvate to pyruvate with pyruvate kinase catalyzing the reaction (Berg, Tymoczko & Stryer, 2002).
In general, acetylcholine and pyruvate form important intermediates in both anabolic and catabolic processes in living cells. Any imbalance in these intermediates may cause aberrations in cellular processes which can lead to pathologies. For instance, accumulation of pyruvate has been blamed for causing beriberi. This implies that the production and uptake of metabolic intermediates is critical to keep and maintain the normal physiology of cells. Reference: Berg, J. M. , Tymoczko, J. L. , & Stryer, L (2002). Biochemistry (2 Ed). Michigan: W. H. Freeman and Company and Sumanas, Inc.