AP BIOLOGY

Detailed explanation-1: -Pyruvate, derived from glycolysis, is firstly converted into acetyl-CoA (2-C) which is subsequently condensed with oxaloacetate (4-C) to form the 6-C compound citrate. This is cycled back to oxaloacetate via a series of reactions which form CO2 (as a waste product) as well as NADH and FADH.

Detailed explanation-2: -Two pyruvates are converted to two lactic acid molecules, which ionize to form lactate. In this process two NADH + H+ are converted to two NAD+. Our muscle cells can undergo this process when they are in oxygen debt.

Detailed explanation-3: -Cellular Respiration Stage II: The Krebs Cycle. Recall that glycolysis, stage I of cellular respiration, produces two molecules of pyruvate. These molecules enter the matrix of a mitochondrion, where they start the Krebs cycle.

Detailed explanation-4: -Glycolysis starts with one molecule of glucose and ends with two pyruvate (pyruvic acid) molecules, a total of four ATP molecules, and two molecules of NADH.