Exam 1

Question 1

What enzyme initiates bile acid synthesis from cholesterol?

Answer 1

cholesterol 7α-hydroxylase

Question 2

What 3 things decrease activity HMG-CoA reductase?

Answer 2

1. Glucagon
2. Epinephrine
3. AMPK

Question 3

What upregulates HMG-CoA reductase?

Answer 3

Low cellular sterol level - SREBP dissociates from SCAP moves to nucleus (TF)

Question 4

What are 4 mechanisms for regulating cholesterol synthesis and transport?

Answer 4

1. Covalent modification of HMG-CoA reductase
2. Transcriptional regulation of HMG-CoA reductase
3. Activation of ACAT - storage
4. Transcriptional regulation of LDL-R

Question 5

SR-B1 expression is _________ with regards to atherosclerosis.

Answer 5

Protective

Question 6

PLTP

Answer 6

1. Catalyzes transfer of phospholipids between lipoprotein classes
2. Needed for maximal activity of LCAT (HDL)

Question 7

What tissues express ABCG1 and what is its function?

Answer 7

1. Spleen, thymus, lung, brain, liver, and macrophages

2. Promotes cholesterol efflux to HDL

Question 8

Absence of ABCA1 (Tangier Disease) results in what?

Answer 8

1. Near-absence of normal HDL particles - no discoidal or spherical HDL

Question 9

ABCA1 helps release ____________ to apoA1 to make ________.

Answer 9

1. Free cholesterol

2. Discoidal HDL

Question 10

Lp(a)

Answer 10

LDL-like where apoB-100 is covalently bound to apolipoprotein(a) - variable due to Kringle IV repeats in LPA gene

Question 11

Lp(a) is a _____________ for cardiovascular disease.

Answer 11

Risk factor

Question 12

What is the most effective way to modulate plasma LDL-C levels?

Answer 12

Manipulation of hepatic LDL-R gene expression

Question 13

Thyroxine and ________ enhance LDL-R gene expression.

Answer 13

Estrogen

Question 14

VLDL remnants become IDL and LDL. C apolipoproteins and ______ redistribute to _____.

Answer 14

1. ApoE

2. HDL

Question 15

ACAT-1 is to ________ as ACAT-2 is to liver and intestine.

Answer 15

Macrophages, foam cells, adrenocortical cells and skin

Question 16

Mutations in ABCG5/G8 cause what disease?

Answer 16

Sitosterolemia - absorb unusually large amounts of plant sterols - tendon and subcutaneous xanthomas

Question 17

Where does ezetimibe act?

Answer 17

Blocks NPC1L1 to prevent cholesterol absorption in the intestine.

Question 18

ASCVD

Answer 18

Heart attacks, strokes, and peripheral artery disease

Question 19

CAD

Answer 19

Coronary atherosclerosis disease

Question 20

Lipid disorders that cause ASCVD (4)

Answer 20

1. Elevated TC or LDL
2. Excess apoB lipoproteins - metabolic syndrome/Familial Hyperchol
3. Depressed HDL
4. Elevated Lp(a)

Question 21

Lowering LDL with ______ lowers risk.

Answer 21

Statins

Question 22

Reduced action of SLCO1B1 can lead to what?

Answer 22

Dec. hepatic uptake and Inc. statin concentration in the blood

Question 23

What is the only mechanism for cholesterol excretion?

Answer 23

Conversion to bile salts

Question 24

What converts fibrinogen to fibrin(glue)?

Answer 24

Thrombin

Question 25

What is primarily responsible for the degradation of fibrin clots?

Answer 25

Plasmin

Question 26

What is the lifespan of a platelet?

Answer 26

7-10 days

Question 27

What factor is the convergence point between the extrinsic and intrinsic pathway?

Answer 27

Factor Xa

Question 28

How are platelets activated?

Answer 28

Activate P2Y1/P2Y12 R stimulate COX and GPIIb/IIIa - fibrinogen cross-links
COX mediated –> TXA2/PGI2

Thrombin can activate platelets too

Question 29

What leads show the inferior wall?

Answer 29

II, III, aVF (RCA)

Question 30

What leads show the lateral wall?

Answer 30

I, aVL, V5, V6 (CIRC)

Question 31

What leads show the anterior wall

Answer 31

V2-V4 (LAD)