10.1 Acetyl-CoA

Question 1

How does Acetyl-CoA drive reactions?

Answer 1

Hydrolysis of high-energy thioester bond

Question 2

Complex that forms Acetyl-CoA?

Answer 2

Pyruvate Dehydrogenase Complex

Question 3

Step 1 of Pyruvate Dehydrogenase Complex

Answer 3

Pyruvate Dehydrogenase (PDH) oxidizes pyruvate making CO2. Remaining Cs bind to TPP.

*Also uses Mg2+ and Vitamin B1

Question 4

Step 2 of Pyruvate Dehydrogenase Complex

Answer 4

Dihydrolipoyl Transacetylase oxidizes 2Cs left with lipoic acid. Acetyl group transferred to CoA making Acetyl-CoA

Question 5

Step 3 of Pyruvate Dehydrogenase Complex

Answer 5

Dihydrolipoyl Dehydrogenase uses FAD to reoxidize lipoic acid making FADH2 .
FADH2 can transfer to NAD+ to form NADH to go into ETC.

Question 6

What does Pyruvate Dehydrogenase Kinase do?

Answer 6

Phosphorylates PDH when ATP or Acetyl-CoA lvls are high. Turns it off.

Question 7

What does Pyruvate dehydrogenase phosphatase do?

Answer 7

Dephosphorylates PDH when ADP lvls are high. Turns it on.

Question 8

1st Step in Acetyl-CoA formation from fatty acids

Answer 8

Fatty acid and CoA couple in cytosol, make fatty acyl-CoA.

Moves to intermembrane space

Question 9

2nd Step in Acetyl-CoA formation from fatty acids

Answer 9

Forms acyl-carnitine.

Crosses inner membrane

Question 10

3rd Step in Acetyl-CoA formation from fatty acids

Answer 10

Acyl group becomes fatty acyl-CoA again after transfer to mitochondrial CoA.

Beta oxidation makes it acetyl-CoA

Question 11

Three ways Acetyl-CoA can be formed

Answer 11

From carbon skeletons of ketogenic AAs, ketone bodies, and alcohol