[Campbell Biology P.233] Which of the following statements accurately distinguishes between ... | Practice Question
Which of the following statements accurately distinguishes between oxidative phosphorylation and substrate-level phosphorylation in cellular respiration?
A: Oxidative phosphorylation occurs in glycolysis, while substrate-level phosphorylation occurs in the electron transport chain.
B: Oxidative phosphorylation generates a small amount of ATP, whereas substrate-level phosphorylation generates a large amount.
C: Oxidative phosphorylation directly uses energy from the transfer of a phosphate group from a phosphorylated substrate to ADP, while substrate-level phosphorylation uses energy from a proton gradient.
D: Oxidative phosphorylation is coupled to the electron transport chain and chemiosmosis, whereas substrate-level phosphorylation involves the direct transfer of a phosphate group from an organic substrate to ADP.
Explanation
Oxidative phosphorylation relies on the energy released from the electron transport chain to create a proton gradient chemiosmosis , which then powers ATP synthase to produce ATP. Substrate-level phosphorylation, in contrast, occurs when an enzyme directly transfers a phosphate group from a high-energy organic molecule to ADP, forming ATP.