Review 4 Cholesterol and Cholesterol Esters

Question 1

What is the rate limiting enzyme in cholesterol biosynthesis?

Answer 1

HMG CoA REDUCTASE

Question 2

What is the reaction of HMG CoA reductase?

Answer 2

HMG CoA–>Mevalonic Acid

Question 3

What do statins inhibit

Answer 3

HMG CoA reductase

Question 4

What has a negative feedback on HMG-CoA reductase

Answer 4

Cholesterol

Question 5

What 2 things is cholesterol used to make?

Answer 5

1. Bile Acid

2. Cholesterol Esters

Question 6

What enzyme makes cholesterol into bile acids?

Answer 6

7-alpha-hydroxylase

Question 7

What makes cholesterol into cholesterol esters?

Answer 7

Acyl-CoA acyltransferase

ACAT

Question 8

What 3 things does excess cholesterol lead to?

Answer 8

1. Inhibits HMG-CoA reductase
2. Activates ACAT
3. Activates 7-alpha-hydroxylase

Question 9

What are the 3 limiting enzymes in lipid metabolism?

Answer 9

1. Acyl-CoA acyltransferase (ACAT)
2. Hormone sensitive triacylglycerol lipase
   (HSTL)
3. Carnitine palmitoyl transferase 1
   (CPT-1)