AP BIOLOGY

Detailed explanation-1: -It takes place in the folds of the inner membrane of the mitochondria. These folds are called cristae. In this step of cellular respiration, electron carriers NADH and FADH2 drop off the electrons they’ve carried from the citric acid cycle. This drop-off allows a large number of ATP molecules to form.

Detailed explanation-2: -The oxidation of one molecule of NADH thus leads to the synthesis of three molecules of ATP, whereas the oxidation of FADH2, which enters the electron transport chain at complex II, yields only two ATP molecules.

Detailed explanation-3: -These carriers take the electrons from NADH and FADH2, pass them down the chain of complexes and electron carriers, and ultimately produce ATP. More specifically, the electron transport chain takes the energy from the electrons on NADH and FADH2 to pump protons (H+) into the intermembrane space.

Detailed explanation-4: -NADH and FADH2 carry high-energy electrons to the electron transport chain in cellular respiration. NADPH carries high-energy electrons to the electron transport chain in photosynthesis.