Oxidative Phosphorylation

Question 1

Names of the four complexes of the ETC in order

Answer 1

1. NADH:ubiquinone oxireductase
2. Succinate dehydrogenase
3. Cytochrome C reductase
4. Cytochrome C oxidase

Question 2

Which complexes transport H+ into the intermembrane space?

Answer 2

Complexes I, III and IV

Question 3

Where does NADH donate electrons?

Answer 3

To NADH:ubiquinone reductase

Question 4

Which complex is part of the TCA cycle?

Answer 4

Complex II, involved in succinate to FAD reaction

Question 5

Between which complexes does ubiquinone transport electrons?

Answer 5

Complexes I, II and III

Question 6

What electron carrier transports electrons between complex III and IV?

Answer 6

Cytochrome C

Question 7

Where do the electrons of NADH & FADH2 ultimately end up?

Answer 7

In H2O after reducing O2

Question 8

What two experiments were used to test if a proton gradient was necessary for ATP formation? Describe the basic characteristics.

Answer 8

1. BR was used as a proton pump to fill a certain membrane with protons. Only works with light added. ATPase was added. Ultimately, ATP was only created in the presence of light.
2. When adding DNP, it slipped through the membrane, carrying out protons. ATP was no longer created from the addition of DNP.

Question 9

Main groups of subunits in ATPase

Answer 9

1. Fc: Membrane-bound unit (multiple protein subunits, rotating c units, proton channel)
2. Rotor: Rotation imparted to central stalk. Gamma subunit rotates and couples F1 and F0.
3. F1: ATP synthesis site. The energy to form ATP is derived from the tightly bound gamma subunit. There are three subunits with low, medium or high affinity for the nucleotide (adenine). Movement of gamma subunit also involved in releasing newly synthesised ATP

Question 10

How the ADP / ATP antiport is driven

Answer 10

High concentrations of ADP