What is the role of pyruvate in glycolysis?

Pyruvate is the end product of glycolysis, which is then used in the Krebs cycle for further energy production.

In the process of glycolysis, glucose, a six-carbon sugar, is split into two molecules of a three-carbon sugar. This process occurs in ten steps and is split into two phases: the energy investment phase and the energy payoff phase. The energy investment phase uses two ATP molecules to phosphorylate glucose, which is then split into two three-carbon molecules. In the energy payoff phase, these three-carbon molecules are oxidised to produce pyruvate, and ATP and NADH are generated.

Pyruvate plays a crucial role in this process as it is the final product of glycolysis. Each glucose molecule produces two pyruvate molecules, two ATP molecules (net gain), and two NADH molecules. The ATP produced is used directly for energy, while the NADH molecules are used in the electron transport chain to produce more ATP.

After glycolysis, the pyruvate molecules are transported into the mitochondria, where they are further oxidised in the Krebs cycle. This is another series of reactions that generate more ATP and NADH, as well as FADH2, another molecule used in the electron transport chain. The Krebs cycle also produces carbon dioxide as a waste product, which is exhaled by the organism.

In summary, pyruvate is a key molecule in cellular respiration. It is the end product of glycolysis and is used in the Krebs cycle for further energy production. Without pyruvate, the cell would not be able to produce as much ATP, and the process of cellular respiration would be less efficient.