B-Oxidation

Question 1

Steps of B-oxidation

Answer 1

1. Activation
2. Transport
3. Oxidation

Question 2

Activation step

Answer 2

Enzyme: Acyl-CoA synthetase
Requires ATP
Process: FA converted to acyl coa

Question 3

Transport

Answer 3

Acyl CoA is transported into the mitochondrial matrix via palmitoyl transferase
Carnitine palmitoyl transferase 1: Transport Acyl CoA to the mitochondrial matrix and converts to acylcarnitine
Carnitine palmitoyl transferase 2: Transports acylcarnitine back into matrix and converts it back to fatty acyl coa

Question 4

Step 1 of the oxidation

Answer 4

Acyl-CoA dehydrogenase converts fatty acyl coa to trans-enoyl coa and produces QH2

Question 5

Step 2 of the oxidation

Answer 5

Enoyl-CoA hydratase uses water to convert trans-enoyl coa to 3-L-hydroxyacyl coa

Question 6

Step 3 of the oxidation

Answer 6

3-L-hydroxyacyl-coa dehydrogenase converts 3-L-hydroxyacyl coa to B-acetyl-coa and produces NADH

Question 7

Step 4 of the oxidation

Answer 7

B-ketoacyl-CoA thiolase converts B-ketoacyl coa to Fatty acyl coa and acetyl coa using a coash

Question 8

ATP Generation from fatty acid oxidation (palmitoyl coa)

Answer 8

8 Acetyl CoA (810)=80 ATP
7 QH2 (71.5)=10.5
7 NADH (7*2.5)=17.5
Output : 108 ATP
ATP expended to activate palmitate= -2
Net yield = 106 ATP per palmitoyl

Question 9

2 extra enzymes required for B-oxidation of unsaturated fatty acids

Answer 9

Enoyl-CoA Isomerase and 2,4-Dienoyl-CoA-Reductase

Question 10

Enoyl-CoA Isomerase

Answer 10

converts one of the cis double bonds to a trans double bond
this occurs because the cis double bond is not favorable for enoyl-coa hydratase

Question 11

2,4-Dienoyl-CoA Reductase

Answer 11

-reduces the diene to one double bond

Question 12

What occurs after 2,4-Dienoyl CoA Reductase?

Answer 12

Enoyl-CoA Isomerase comes back in to move the double bond to the correct a,b position

Question 13

What is the correct a,b position for the double bond in linoleoyl coa?

Answer 13

connected to the carbonyl carbon

Question 14

3 enzymes required for odd chain b-oxidation

Answer 14

Propinoyl coa carboxylase ​

Methylmalonyl-coa racemase

Methylmalonyl-coa mutase