ETC- Electron Transport Chain

• happens in the cristae- the inner membrane of the mitochondria
• start with NADH + FADH2
• NADH is a powerful reducing agent
• NADH gets oxidized to NAD+ at the beginning of ETC
• a lot/ most of the energy sits in NADH
• pumping/ actively transporting H+ ions across the gradient
• pumping H+ ions into the outer membrane space
• FADH gets oxidized to FAD+
• there is a significantly less amount of FADH in ETC so it is not responsible for creating as much of the membrane gradient
• FADH can go back to the Krebs Cycle
• Water is reduced and 2 H+ ions are formed
• Oxygen is introduced at the end of ETC and it attracts the electrons that have moved down the chain to create water
• the H+ ions help create the grdadient
• ATP Synthase is a molecular motor that helps transport H+ ions into and out of the membrane to create a gradient
• when H+ ions move through ATP Synthase it is called proton motive force
• protons flow from high concentration (intermembrane space) to low concentration (matrix)
• The spinning of the molecular motor of ATP Synthase contributes to chemiosmosis
• the H+ ions that create the proton motive force in chemiosmosis

  grab free phosphates and ADP to make a boat load of ATP
• the total count of ATP produced in ETC is around 32-34 molecules
• the processes of chemiosmosis and creating ATP in the electron transport chain also contribute to oxidative phosphorylation
• ATP synthase is a coupled reaction- the H+ ions are pumped out to further the electrons down the chain (this will occur even if oxygen is present)
• oxygen attracts electrons and H+ ions