Question

1. Acetyl CoA carboxylase . . .

A. is activated by citrate

B. is activated by palmitate or palmitoyl SCoA

C. is the rate-determining step of fatty acid breakdown

D. B and C above

E. A and B above

2. High density lipoproteins particles . . .

A. transport endogenous lipids

B. transport cholesterol from the liver to the tissues, predominantly

C. A and B above

D. None of the above above

3. Adipocytes . . .

A. store large amounts of glycogen

B. store triacylglycerols

C. contain the enzyme adenylate cyclase

D. A and C above

E. B and C above

4. Fatty acid breakdown . . . . . . . .

A. produces acetyl CoA

B. produces palmitate

C. Produces NADPH

D. A, B, and C above

E. A and C above

Answer 1

1) Acetyl- CoA carboxylase is a enzyme that catalyses irreversible carboxylation of Acetyl CoA to produce Malonyl-CoA.

Citrate activates Acetyl-CoA carboxylase. Citrate increases Acetyl-CoA carboxylase polymerisation that increase the enzyme activity. Glutamate also activates Acetyl-CoA carboxylase by allosterically.

2) High density lipoproteins participates in the reverse cholesterol transport process whereby excess cholesterol in cells in the periphery is transported to the liver.Low density lipoproteins is the main carrier of circulating cholesterol within the body

3) Adipocytes function is storing energy as fat. There are two type of adipose tissue, one is White adipose tissue and another is brown adipose tissue. In white adipose tissue fat is stored is in a semi liquid state, and is composed primarily of triglycerides and cholersteryl Ester.

4) Fatty acid degradation is the process in which fatty acids are broken down into their metabolites, in the end generating acetyl-CoA. it include mainly three major steps

*Lipolysis of and release from adipose tissue
*Activation and transport into mitochondria
* β-oxidation

In beta oxidation NADPH produces