AP BIOLOGY

Detailed explanation-1: -Glycolysis can generate ATP in the absence of oxygen. This is described as anaerobic metabolism. It results from substrate-level phosphorylation. This is distinct from oxidative phosphorylation that occurs in the mitochondria.

Detailed explanation-2: -Substrate-level phosphorylation is the production of ATP from ADP by a direct transfer of a high-energy phosphate group from a phosphorylated intermediate metabolic compound in an exergonic catabolic pathway.

Detailed explanation-3: -Fermentation does not involve an electron transport chain and does not directly produce any additional ATP beyond that produced during glycolysis by substrate-level phosphorylation. Organisms carrying out fermentation typically produce a maximum of two ATP molecules per glucose during glycolysis.

Detailed explanation-4: -During glycolysis, glucose ultimately breaks down into pyruvate and energy; a total of 2 ATP is derived in the process (Glucose + 2 NAD+ + 2 ADP + 2 Pi–> 2 Pyruvate + 2 NADH + 2 H+ + 2 ATP + 2 H2O).