Lipoprotein Pathways and Cholesterol

Question 1

Cholesterol use in all cells

Answer 1

Stabilize plasma membrane

Question 2

Cholesterol use in liver

Answer 2

Precursor to bile acids (BA)

Question 3

Cholesterol use in adrenal cortex & gonads

Answer 3

Precursor for steroid hormone synth

Question 4

Bile acid synth enzyme

Answer 4

BA synthase

Question 5

Cholesterol converted to steroid hormones by ______

Answer 5

P450 enzymes in adrenal cortex and gonads

Question 6

Cholesterol esters (CE)

Answer 6

cholesterol storage form for cells that use cholesterol as a precursor

Consist of oil droplets

Question 7

Cholesterol structure

Answer 7

Ampiphatic
Insoluble
Convert to CE for storage

Question 8

Lipoproteins used for…?

Answer 8

How cholesterol, TG, PL, and CE are transported in blood

Question 9

Cholesterol Esterase

Answer 9

Release cholesterol from CE

Question 10

FA transport

Answer 10

Plasma proteins

Question 11

Lipoprotein structure

Answer 11

CE & TG in oily core
Chol & PL form lipid surface
Apoproteins line surface as well

Question 12

TG-rich LPs

Answer 12

CM (larger of the two)

VLDL

Question 13

Intermediate remnant LPs

Answer 13

CMR
IDL
TG ~= CE

Question 14

Cholesterol rich LPs

Answer 14

LDL

HDL (smallest)

Question 15

Apoprotein

Answer 15

At least one on each LP
Required for LP synth and stability
Expressed by cells that secretes the LP
Can associate/dissociate from LP surface

Question 16

ApoB48

Answer 16

Structural for CM & CMR

Question 17

ApoB100

Answer 17

Structural for VLDL & its remnants IDL & LDL

Ligand for LP-R

Binds LDL-R on liver & other cells

Question 18

ApoA1

Answer 18

Structural for HDL

Required by lecithin-cholesterol acyl transferase (LCAT) to convert chol –> CE

Question 19

ApoCII

Answer 19

Required enzyme cofactor for lipoprotein lipase (LPL) to remove TG –> release FA + glycerol & create remnant LP