AP BIOLOGY

Detailed explanation-1: -In eukaryotic cells, the pyruvate molecules produced at the end of glycolysis are transported into mitochondria, which are the sites of cellular respiration. There, pyruvate will be transformed into an acetyl group that will be picked up and activated by a carrier compound called coenzyme A (CoA).

Detailed explanation-2: -In order for pyruvate from glycolysis to enter the Kreb’s Cycle it must first be converted into acetyl-CoA by the pyruvate dehydrogenase complex which is an oxidative process wherein NADH and CO2 are formed. Another source of acetyl-CoA is beta oxidation of fatty acids.

Detailed explanation-3: -2: The Krebs Cycle completes the breakdown of glucose begun in glycolysis. If oxygen is present, pyruvate enters the mitochondria and is converted to acetyl-CoA. Acetyl-CoA enters the cycle by combining with 4-carbon oxaloacetate.

Detailed explanation-4: -Cellular Respiration Stage II: The Krebs Cycle. Recall that glycolysis, stage I of cellular respiration, produces two molecules of pyruvate (also known as pyruvic acid). These molecules enter the matrix of a mitochondrion, where they start the Krebs cycle.

Detailed explanation-5: -The stages of cellular respiration include glycolysis, pyruvate oxidation, the citric acid or Krebs cycle, and oxidative phosphorylation.