AP BIOLOGY

Detailed explanation-1: -The electron transport chains are on the inner membrane of the mitochondrion. As the high-energy electrons are transported along the chains, some of their energy is captured. This energy is used to pump hydrogen ions(from NADH and FADH2) across the inner membrane, from the matrix into the intermembrane space.

Detailed explanation-2: -The electrons from from NADH and FADH2 flow through the electron transport chain in the inner mitochondrial membrane generating a H+ buildup in the inner membrane space.

Detailed explanation-3: -Energy from the electrons is used by proteins in the electron transport chain to pump H+ ions from the stroma into the thylakoid space. At the end of the electron transport chain, the electrons pass to photosystem I.

Detailed explanation-4: -A photon of light hits chlorophyll, causing an electron to be energized. The free electron travels through the electron transport chain, and the energy of the electron is used to pump hydrogen ions into the thylakoid space, transferring the energy into the electrochemical gradient.

Detailed explanation-5: -In cellular respiration, hydrogen ions (protons) move down their concentration gradient through a membrane protein to produce ATP. The gradient of protons is established by the electron transport portion of oxidative phosphorylation, which is used to transfer protons into the intermembrane space.