Oxidative Phosphorylation

Question 1

Location

Answer 1

Inner membrane

Question 2

Energy

Answer 2

Electron protein channel activity helps to provide the energy for the phosphorylation of ADP and Pi to ATP

Question 3

Steps

Answer 3

1. NADH and FADH are passed to the electron transport chain
2. Both release their hydrogens. Hydrogen is split into two ;electron and proton
3. Energetic Electron passes the first electron carrier of series
4. Electron moves from one carrier with a higher energy to the other carrier at a lower energy. They release energy
5. Energy is used to transport proton from matrix to inter-membrane through transport protein channel
6. This established a proton gradient ( inter-membrane has higher concentration)
7. The proton now moves down the concentration gradient through the channel via facilitated diffusion
8. The protein channel is associated with ATP Synthase, the enzyme to synthesis ATP
9. As the proton moves down, the energy released is used to drive the ATP synthase
10. The transfer of 3 proton, allows the production of 1 ATP is made, provided that ADP and Pi are present

Question 4

oxygen acts as___? What happens if its doesn’t accept?

Answer 4

Oxygen acts as the final electron acceptor, electron and proton are transferred to oxygen and it is reduced to from water molecule.

• if oxygen does not accept electron, the electron protein channel cannot continue as electron have nowhere to go
• If oxygen does not accept electron, FADH2 and NADH cannot be oxidized and reformed back to NAD and FAD, so they cannot act be used in further hydrogen transport

Question 5

Energy yield

Answer 5

theoretically, 1 NADH=3ATP
1 FADH2=2ATP
however this can only happen if ADP and Pi is present. 25% of the energy yield is used to transport substances like ADP to mitochondria and ATP to cytoplasm.

Question 6

electron transport chain

Answer 6

• a series of electron carried in the inner membrane
• Is next to one another so that electron can be passed easily from one carrier to another
• Inner membrane is impermeable to hydrogen ion, so these electron carriers are required to pump proton across the membrane to establish a proton gradient