Energy Production From Lipids

Question 1

What are lipids?

Answer 1

Compounds that are generally insoluble in water but are soluble in organic solvents. More reduced that carbs

Question 2

What are the three classes of lipids?

Answer 2

Fatty acid derivatives, hydroxy-methyl-glutaric acid derivatives and fat soluble vitamins

Question 3

Give some examples of fatty acid derivatives

Answer 3

TAGs, phospholipids, eicosanoids

Question 4

Give some examples of hydroxy-methyl-glutaric acid derivatives

Answer 4

Ketone bodies, cholesterol, cholesterol esters, bile acids and salts

Question 5

What are the fat soluble vitamins?

Answer 5

ADEK

Question 6

What enzyme hydrolyses TAGs and what are they hydrolysed to?

Answer 6

Pancreatic lipase in the small intestine. Hydrolysed to release glycerol and fatty acids. Requires bile salts and a protein cofactor (colipase)

Question 7

Where does glycerol metabolism occur?

Answer 7

Liver

Question 8

Which enzyme is used in the following reaction: glycerol —> glycerol phosphate
ATP —> ADP

Answer 8

Glycerol kinase

Question 9

Which fatty acid is the starting point for eicosanoid synthesis?

Answer 9

Arachidonic acid

Question 10

List 3 ketone bodies produced in the body

Answer 10

Acetoacetate, acetone and beta-hydroxybutyrate

Question 11

Which ketones are synthesised in the liver?

Answer 11

Acetoacetate and beta-hydroxybutyrate

Question 12

Which enzyme catalyses the following reaction:

glycerol —> mavalonate

Answer 12

Reductase

Question 13

Which enzyme catalyses the following reaction:

3 acetyl Co A —> glycerol

Answer 13

Synthase

Question 14

Which enzyme catalyses the following reaction:

glycerol —> acetoacetate

Answer 14

Lyase

Question 15

A high insulin:glucagon ratio means what for ketone synthesis?

Answer 15

Inhibited because insulin is present thus glucose is taken up into cells and used

Question 16

What is necessary for ketone bodies to be produced?

Answer 16

Available fatty acids, low insulin:glucagon ratio (activates lyase)

Question 17

List 4 compounds which can be catabolised to produce acetyl Co A

Answer 17

Fatty acids, sugars, alcohol and certain amino acids

Question 18

Where does beta-oxidation occur and what are the implications of this?

Answer 18

Mitochondria therefore it cannot occur in RBC