Electron Transport Chain

Question 1

Where is the ETC located?

Answer 1

In the mitochondrial matriX

Image:

Question 2

What is the first step of Complex I?

Answer 2

NADH is oxidized by FMN (flavin mono-nucleotide). FMN becomes FMNH2, and is oxidized by Fe-S, which is then oxidized by Coenzyme Q (ubiquinone)

Formula:

Question 3

How is Ubiquinone Reduced in Complex II?

Answer 3

Succinate ( ) is oxidized to Fumarate ( ) by FAD, reducing it to FADH2. FADH2 is oxidized by Fe-S which is once again reduced and then oxidized by coenzyme Q.

Formula:

Question 4

What is the net product of Complex I?

Answer 4

CoQH2 and NAD+

Question 5

What is the net product of Complex II?

Answer 5

Fumarate and CoQH2

Question 6

What happens in Complex III?

Answer 6

Cytochrome c with Iron oxidizes both CoQH2, losing 4H to the inter membrane space. 4 electrons are transferred.

Question 7

What happens in the Complex IV?

Answer 7

Cytochrome c’s 4 electrons are transferred to oxygen.

Question 8

Products of Complex IV

Answer 8

2 water molecules

Question 9

Proton Motive Force

Answer 9

A type of Electrochemical Gradient. The movement of Hydrogens into the inter membrane space can decrease the pH (more acidic) and causing a voltage difference between inter membrane=e and matrix.

Question 10

What are the two types of shuttles used by NADH to cross the mitochondrial matrix?

Answer 10

Glycerol 3-phosphate and Malate- aspartate

Question 11

How much ATP is produced from the Glycerol 3-phosphate pathway?

Answer 11

1.5 ATP produced from this pathway

Question 12

How much ATP is produced from the use of the Malate-aspartate shuttle?

Answer 12

2.5 ATP