Final answer:
Pyruvate is a 3-carbon molecule that is the end product of glycolysis. It can enter the mitochondria and be converted into acetyl CoA, which is necessary for the citric acid cycle.
Step-by-step explanation:
What Is Pyruvate?
Pyruvate is a critical biochemical molecule and the end product of glycolysis, which is a series of reactions that break down glucose, a six-carbon sugar molecule, into two three-carbon compounds. The chemical formula for pyruvate is C3H4O3, which reflects its three-carbon structure. During glycolysis, the glucose molecule (C6) is split into two 3-carbon pyruvate molecules, releasing some chemical energy that is captured in the form of ATP (adenosine triphosphate) and NADH, which are used for cellular energy and electron transport, respectively.
After glycolysis, if oxygen is available, pyruvate enters the mitochondria of eukaryotic cells where it undergoes several changes. A three-step conversion process transforms pyruvate into acetyl coenzyme A (acetyl CoA), essential for entry into the citric acid cycle (Krebs cycle). The conversion involves an oxidative decarboxylation reaction catalysed by the pyruvate dehydrogenase enzyme complex, resulting in the release of one CO2 molecule and the production of one NADH molecule for each pyruvate transformed.