Lipid Metabolism

Question 1

Give the main function of triacylglycerol, cholesterol, glycolipids and phospholipids

Answer 1

Triacylglycerol - main energy storage in orgs.

Cholesterol - component of cell membranes and a precursor to synthesis of steroids and bile salts

Glycolipids and phospholipids - important for synthesis of cell membranes

Question 2

Where are triacylglycerols found?

Answer 2

Found in blood bound to lipoproteins, which keeps the insoluble lipids in an aqueous environment

Question 3

How do triacylglycerols get broken down?

Answer 3

Triacylglycerols are hydrolysed into glycerol and free fatty acids in capillaries of adipose tissues and skeletal muscles and absorbed by them

Question 4

What happens to glycerol?

Answer 4

Glycerol is transferred to the liver and the kidney to participate in gluconeogenesis (synthesis of glucose)

Question 5

What does fatty acid synthesis consist of?

Answer 5

Condensation of two carbon units (acetyl CoA) to form long hydrocarbon chains carried out by fatty acid synthase

This reaction takes place in cytosol and uses NADPH as a reducing agent

Question 6

How is Acetyl CoA brought into cytosol from the mitochondrial matrix for FA synthesis?

Answer 6

Acetyl CoA can’t cross so it crosses mitochondria as citrate