1. Electron transport chain (ETC)
SBI4U

2. Location
Membrane proteins between the matrix and intermembrane space.

3. Purpose
To release the energy stored in NADH and FADH2 and use it to make ATP
NADH
FADH2

4. Major Reactants
NADH
FADH2 O2

5. Major Products
ATP
H2O

6. Details
NADH and FADH2 release the electrons and protons trapped during the first 3 stages
Electrons pass along a series of coenzymes/electron acceptors releasing energy along the way
Energy is used to pump protons out of the matrix and into the intermembrane space
This creates a [gradient] with a [H+] in the intermembrane space

7. Proton Pumps Series of oxidations and reductions between proteins
cytochromes
Series of oxidations and reductions between proteins

8. More Details The ETC produces the most ATP of the 4 stages.
Each NADH and FADH2 is oxidized and the energy from its electrons is used to pump H+ ions
The electrons from NADH and FADH2 are passed from protein to protein until they arrive at the final electron acceptor, oxygen.
Oxygen then combines with 2 H+ to make H2O.

9. After building up the [H+]
Protons diffuse back into the matrix through a channel called ATP synthetase and ATP is formed.
Oxidative Phosphorylation

10. As H+ is pumped into the intermembrane space an electrical gradient occurs across the inner membrane and the matrix occurs.
The energy generated by this electrical gradient is called a proton motive force.
The H+ diffuse through ATPase and for each H+ that diffuses back into the matrix through the enzyme 1 ATP is produced.

11. What is Chemiosmosis?
Its when the H+ pass back across the membrane into the matrix
As the H+ move through the ATP synthetase, their energy is used to combine ADP + Pi to make ATP

12. How much ATP? *
* NB: The NADH from glycolysis only produce 2 ATP in the ETC.

14. Can we get energy from other food sources?

15. metabolism of lipids and proteins will also yield ATP...
…see the end of chapter 5 for more details on that!!!!