In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP+P1 to ATP?
A. Energy released as electrons flow through the ETC
B. energy released from substrate-level phosphorylation
C. Energy released from ATP synthase pumping hydrogen ions from the mitochondrial matrix
D. Energy released from movement of protons through ATP synthase
E. No external source of energy is required because the reaction is exergonic
Answer: D