Oxidative Phosphorylation

Question 1

Describe oxidative phosphorylation

Answer 1

1. H atoms are released from reduced NAD and reduced FAD as they’re oxidised to NAD and FAD. The H atoms split into protons (H+) and electrons (e-)
2. The electrons move down the ETC (made up of electron carriers) loosing energy at each carrier
3. This energy is used by electron carriers to pump protons from the mitochondrial Matrix into the intermembrane space
4. Forming an electrochemical gradient, as the concentration of protons is higher in the intermembrane space then the mitochondrial matrix
5. Protons then move down the electrochemical gradient, into the mitochondrial matrix, via ATP synthase. This movement dries the synthesis of ATP from ADP+P
6. This process of ATP production driven by movement of H+ ions across a membrane is called chemiosmosis
7. In the mitochondrial matrix at the end of the transport chain, protons, electrons and o2 (from the blood) combine to form water. Oxygen is said to be the final electron acceptor
8. Total ATP produced is 32

Question 2

Why’s it called oxidative phosphorylation

Answer 2

The movement of electrons along the chain is due to oxidation. The energy from the electrons combines inorganic phosphate and ADP to form ATP=phosphorylation

Question 3

The surface of the inner mitochondrial membrane is highly folded to form Cristae, state one advantage of this arrangement to the electron transfer chain

Answer 3

Provides a large SA of membrane incorporating the coenzymes (NAD/FAD) and electron carriers that transfer electrons along the chain

Question 4

The Oxygen taken up by organisms has an important role in aerobic respiration. Explain this role

Answer 4

Oxygen is the final acceptor or the electrons and hydrogen ions (protons) in the electron transfer chain. Without it the electrons would accumulate along the chain and respiration would cease