W3-4 Cholesterol Metabolism

Question 1

Ultimate precursor of all cholesterol synthesized de novo

Answer 1

Acetyl-CoA

Question 2

How many carbons is cholesterol? Made from how many acetyl-CoAs?

Answer 2

27 C

from 15 acetyl-CoAs

Question 3

Rate determining/drug targeting step

Answer 3

HMG-CoA reductase

blocked by statins

Question 4

How is cholesterol synthesis regulated on transcription level?

Answer 4

Question 5

What promotes the degradation of HMG-CoA reductase?

Answer 5

High sterol levels

Question 6

How is HMG-CoA reductase regulated on a whole-body metabolism level?

Answer 6

Question 7

2 ways liver ships cholesterol

Answer 7

VLDLs

bile acids

Question 8

Chylomicrons in intestinal epithelium cells

Answer 8

nascent chylomicrons

(nascent means ‘new’)

Question 9

This Apo protein is always present on chylomicrons

Answer 9

ApoB-48

Question 10

HDLs add this apoprotein to chylomicrons to activate them

Answer 10

ApoC II

Question 11

Chylomicrons are mostly what?

Answer 11

TAGs

Question 12

Cholesterol is often bound to what molecule for transport from the liver?

Answer 12

FA

Question 13

This apo protein is always bound to VLDLs

Answer 13

ApoB-100

Question 14

HDLs add which apoprotein to VLDLs to activate them?

Answer 14

ApoC II

Question 15

Draw out VLDL and chylomicron activation and metabilism in blood

Answer 15

Question 16

Familial hypercholesterolemia pathology

Answer 16

LDL receptor miscoding, does not allow LDLs to be endocytosed

Question 17

Xanthoma

Answer 17

subcutaneous fat deposits

Question 18

Describe how atherosclerotic plaques are formed

Answer 18

1. Excess LDLs captured under intima of blood vessels
2. Macrophages consume this fat and become foam cells
3. Foam cells die and leave plaque

Question 19

Three metabolic uses of cholesterol

Answer 19

Membranes

Steroid hormones

Bile acids

Question 20

Congenital adrenal hyperplasia

Answer 20

Disease in women that causes increased androgen synthesis and decreased cortisol and androgen synthesis

Question 21

Steroid hormones act through what type of regulation?

Answer 21

transcriptional