5.7.5(Oxidative phosphoryulation and the chemiosmotic theory)

Define the term chemiosmosis

• The movement of hydrogen ions down their electrochemical gradient through ATP synthase to generate ATP

Define the term oxidative phosphorylation

• Production of ATP using the electron transport chain in the presence of oxygen

Describe the process of oxidative phosphorylation

1. in the matrix, reduced NAD and FAD are reoxidised when they release hydrogens which split into H+ ions and electrons

2. Electrons then flow over the electron transport chain over the proteins

3. As the electrons travel over the chain, some of their energy is used to actively transport H+ ions into the intermembrane space

4. H+ concentration increases in the intermembrane space which generates a H+ gradient

5. The H+ ions then diffuse through ATP synthase down an electrochemical gradient back into the matrix - Chemiosmosis

6. The flow causes a conformational change in the ATP synthase that allows ATP and Pi to combine to for ATP

7. Oxygen then combines with the H+ ions and the electrons from electron transport chain to form water

Describe the structure of the electron transport chain

• The electron transport chain contains carrier proteins

• Each carrier protein contains an iron ion at the core

Describe the use of the iron ion in the electron transport chain

• As electrons travel through the electron carrier proteins, the iron gains an electron and becomes reduced

• The reduced iron can then donate the electron to the iron ion in the next electron carrier in the chain

What is the net gain of ATP per glucose molecule

• 32 ATP molecules

Describe why theoretical ATP is rarely achieved during aerobic respiration

• Some ATP is used to actively transport pyruvate into the mitochondria

• Some ATP is used transport reduced NAD

• Some H+ ions may leak out of through the outer mitochondrial membrane