Oxidative phosphorylation

Oxidative phosphorylation

• generates ATP using the flow of protons through ATP synthase

• occurs across the inner mitochondrial membrane of the cristae

• 4 proteins are involved in the electron transfer chain

Reactants and products of OP

• reactants

  • reduced NAD

  • reduced FAD

  • oxygen

  • ADP and inorganic phosphate

• products

  • NAD

  • FAD

  • water

  • ATP

Stages of OP

• reduced NAD and reduced fad release hydrogen

  • transfers protons and electrons into the mitochondrial matrix

• high energy electrons are passed to an electron carrier from reduced NAD and FAD

• the electrons are passed along a series of electron carrier molecules in the electron transport chain

  • embedded in the inner mitochondrial membrane

• energy is used to actively transport protons across the inner mitochondrial membrane from matrix to intermembrane space

• the accumulation of protons in the intermembrane space sets up a steep electrochemical gradient of protons across the inner membrane

• protons diffuse back into the mitochondrial matrix

  • down electrochemical gradient across the inner membrane

  • facilitated

• releases energy and catalyses the synthesis of ATP from ADP and inorganic phosphate

• oxygen is the final electron acceptor

  • combines with electrons and protons to form water

  • thus maintains concentration gradient

Chemiosmosis

• diffusion of protons across the partially permeable inner mitochondrial membrane

  • down their electrochemical gradient through ATP synthase channels

ATP yield per glucose molecule