ATP is produced in all stages of cellular respiration. Which two statements describe the process of ATP synthesis in the electron transport chain?
A. The ATP synthase spins when the hydrogen ions rush past, acting as a "matchmaker" and grabbing another phosphate group to attach to an ADP molecule.
B. The high concentration of NAD+ acts as a catalyst to speed up the formation of ATP from ADP.
C. The high concentration of hydrogen ions in the intermembrane space allows them to diffuse across the membrane into the matrix.
D. The FADH2 synthase spins as the high-energy electrons rush past, synthesizing ATP from ADP.