β-oxidation and glycerol catabolism

Where does β-oxidation occur

mitochondria

What is the purpose of b-oxidation

The purpose of beta-oxidation is to break down fatty acids into acetyl-CoA molecules, which can then enter the citric acid cycle to produce energy in the form of ATP.

What does each rounds of oxidation remove ?

two carbons at a time to produce acetyl-CoA

For the 16C palmitic acid . What happens when it undergoes β-oxidatio ?

7^th round leaves C16 as acetyl-CoA

Produces eight acetyl-CoA molecules

What happens when Fatty acyl-CoA enters mitochondria ?

Converted to the coenzyme fatty acyl-CoA by acyl-CoA synthetases

Where C2 is C_{β AND} C_α is C3 (functional groups) .

What is the first step of β-oxidation

The first step of β-oxidation is the conversion of a fatty acyl-CoA to a trans-Δ2-enoyl-CoA by acyl-CoA dehydrogenase.

FAD→ FADH2

What are the 3 isozymes of acyl-CoA dehydrogenase ?

oVery-long-chain acyl-CoA dehydrogenase (VLCAD) acts on 12C-18C fatty acyl-CoA

oMedium-chain acyl-CoA dehydrogenase (MCAD) acts on 4C-14C fatty acyl-CoA

oShort-chain acyl-CoA dehydrogenase (SCAD) acts on 4C-8C fatty acyl-CoA

What is the second step of β-oxidation

The second step of β-oxidation is hydration, where double bond of trans-Δ²-enoyl-CoA is converted to a β-hydroxyacyl-CoA by the enzyme enoyl-CoA hydratase.

What is the third step of β-oxidation ?

β-hydroxyacyl-CoA is dehydrogenated to β-ketoacyl-CoA

Catalysed by β-hydroxyacyl-CoA dehydrogenase

NAD+ → NADH

What is the fourth step of β-oxidation ?

Thiolase joins β-ketoacyl-CoA with a free CoA molecule

Causing the binding and splitting of the 2C fragment

Making acetyl-CoA and a truncated fatty acyl-Co

What is made at the end of ONE round of β-oxidation ?

o1 NADH

o1 FADH₂

o1 acetyl-CoA

What is made when 16C palmitic acid undergoes seven rounds of β-oxidation ?

o7 NADH

o7 FADH₂

o8 acetyl-CoA

The acetyl-CoA molecules produce a further

-24 NADH

-8 FADH₂

-8 GTP

•Total product from palmitic acid is 31 NADH, 15 FADH₂, and 8 GTP

How many ATP are made in total from the oxidation of 16C?

108

2 are used to activate B-Oxidation

so 106

Describe the process of glycerol catabolism

Glycerol Catabolism Process:

1. Glycerol is converted to glycerol-3-phosphate.

2. Glycerol-3-phosphate is oxidized to dihydroxyacetone phosphate.by Glycerol-3-phosphate dehydrogenase

3. Dihydroxyacetone phosphate converted to glyceraldehyde-3-phosphate (G3P). Produces NADH

4. ATP is generated through glycolysis.