AP BIOLOGY

Detailed explanation-1: -During electron transport, energy is used to pump hydrogen ions across the mitochondrial inner membrane, from the matrix into the intermembrane space. A chemiosmotic gradient causes hy drogen ions to flow back across the mitochondrial membrane into the matrix, through ATP synthase, producing ATP.

Detailed explanation-2: -In the electron transport chain, electrons are passed from one molecule to another, and energy released in these electron transfers is used to form an electrochemical gradient. In chemiosmosis, the energy stored in the gradient is used to make ATP.

Detailed explanation-3: -Complexes I, III, and IV use the chemical energy of oxidation to pump H+ ions from the mitochondrial matrix to the intermembrane space. This makes an electrical current that separates charge and produces a potential difference across the mitochondrial membrane.

Detailed explanation-4: -The electron transport chain is a series of electron transporters embedded in the inner mitochondrial membrane that shuttles electrons from NADH and FADH2 to molecular oxygen. In the process, protons are pumped from the mitochondrial matrix to the intermembrane space, and oxygen is reduced to form water.

Detailed explanation-5: -At the inner mitochondrial membrane, a high energy electron is passed along an electron transport chain. The energy released pumps hydrogen out of the matrix space. The gradient created by this drives hydrogen back through the membrane, through ATP synthase.