AP BIOLOGY

Detailed explanation-1: -One glucose molecule yields four ATP molecules in total during glycolysis. Since 2 ATP molecules are used up in the first phase of glycolysis, there is a net gain of 2 ATP molecules. In addition, glycolysis results in the production of 2 NADH molecules.

Detailed explanation-2: -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.

Detailed explanation-3: -Glycolysis produces two pyruvate molecules, four ATPs (a net of two ATP), two NADH, and two H2O. Therefore, without the presence of oxygen, glycolysis is the only process that can occur, and only two ATP molecules may be produced for each glucose molecule.

Detailed explanation-4: -Glycolysis produces only two net molecules of ATP per 1 molecule of glucose.

Detailed explanation-5: -How much ATP is produced in all three stages combined? Glycolysis produces 2 ATP molecules, and the Krebs cycle produces 2 more. Electron transport from the molecules of NADH and FADH2 made from glycolysis, the transformation of pyruvate, and the Krebs cycle creates as many as 32 more ATP molecules.