what is pyruvate?

Pyruvate is formed when sugar is broken down for energy in the presence of oxygen (aerobic metabolism).
Pyruvic acid (CH₃COCOOH) is an organic acid. The carboxylate anion of pyruvic acid (CH₃COCOO^- ), is known as pyruvate.

Pyruvate is the end product of glycolysis, which is converted into acetyl coA that enters the Krebs cycle when there is sufficient oxygen available. When the oxygen is insufficient, pyruvate is broken down anaerobically, creating lactate in animals (including humans) and ethanol in plants.