AP BIOLOGY

Detailed explanation-1: -In the process of glycolysis, NAD+ is reduced to form NADH + H+. If NAD+ is not present, glycolysis will not be able to continue. During aerobic respiration, the NADH formed in glycolysis will be oxidized to reform NAD+ for use in glycolysis again.

Detailed explanation-2: -In glycolysis, glucose, a six-carbon sugar, is oxidized and cleaved by enzymes in the cytoplasm of cells to form two molecules of pyruvate, a three-carbon compound (see Figs.

Detailed explanation-3: -* Oxidation of PGAL (2) provides the energy to add a second phosphate, while creating a 2 molecules of NADH. It is the addition of this phosphate which provides the excess ATP yield of the pathway.

Detailed explanation-4: -Energy is harvested in the oxidation of PGAL (H atoms and their electrons are removed), and the coenzyme NAD + is reduced (H atoms and electrons added) to form NADH, a high‐energy compound.