Oxidative phosphorylation

Question 1

Where in the body does it take place?

Answer 1

all tissues/cells with mitochondria

Question 2

Describe what happens in the electron transport chain

Answer 2

1. Complex 1 - NAdh from TCA is oxidised to NAD. H+ that is released is pumped to the intermembrane space by proton pump. e- passed to Q
2. Complex 2 - oxidises FADH2 to FAD. Passes e- to Q
3. Q - passes 2e- to complex 3
4. Complex 3 - oxidises Q and reduces cytochrome C. Acts as H+ pump. Passes 2e- to complex 4
5. Complex 4 - reduces O2 by passing the 2e- to it to form H2O. Acts as proton pump
6. H+ gradient set up across inner mitochondrial membrane

Question 3

Describe what happens after the e- transport chain

Answer 3

1. H+ passes through the FoF1-ATP synthase channel back into mitochondrial matrix
2. Movement causes ATP synthase to spin
3. Converts ADP and Pi to ATP

Question 4

How is oxidative phosphorylation controlled?

Answer 4

• Respiratory control limited by O2 supply
• Dependant on ADP

Question 5

What are the products of oxidative phosphorylation

Answer 5

ATP, H2O, oxidised cofactors NAD+ and FAD