Electron Transport Chain

Oxidative Phosphorylation The purpose of the ETC is to create ATP through “Oxidative Phosphorylation” ATP is created through a series of redox reactions NADH and FADH2 are produced by steps 1-3 of cellular respiration, and are “electron carriers”

Electron Transport Chain SBI 4U: Metablic Processes Electron Transport Chain NADH and FADH2, transfer their electrons (2) to a series of proteins embedded in the inner mitochondrial membrane. FADH2 enters the chain at the second step Section 1.3

ETC proteins The proteins are arranged in order of increasing electronegativity Each protein is reduced by gaining two electrons from the one before it

ETC proteins 3 are “proton pumps” Use the energy from electrons to pump protons (H+) from the matrix to the intermembrane space Each 2 electrons cause 2 H+ to be pumped out

ETC proteins 2 are “electron shuttles” Transport electrons from one pump to the next

ETC and Redox Reactions The protons pumped out create an electrochemical gradient There is more positive charge in the intermembrane space than the matrix H+ want to come back into matrix, but cannot cross inner membrane Protons flow through ATP synthase, driving it to create ATP 2 protons make 1 ATP

Role of oxygen Oxygen is highly electronegative It is the final electron acceptor Takes the 2 electrons from the final proton pump, combine with 2 protons in the matrix to form water What would happen if there isn’t oxygen present?