Unit 4 Quiz 1 and 2

Question 1

All of the following statements about acetyl CoA carboxylase are correct except
A) It catalyzes the rate limiting step of fatty acid synthesis
B) It requires biotin
C) It is inhibited by cAMP-mediated phosphorylation
D) Palmitoyl CoA is an activator
E) Its cellular content responds to changes in fat content in the diet

Answer 1

D) Palmitoyl CoA is not an activator, it’s an inhibitor

Question 2

Bile acids differ from their precursor cholesterol in that they
A) Are not amphipathic
B) Contain an ionizable carboxyl group
C) Contain less oxygen
D) Are synthesized primarily in the intestine
E) Contain more double bonds

Answer 2

B) contain an ionizable carboxyl group

Question 3

Cytosolic fatty acid synthesis requires Acetyl CoA which is provided via _____________ from the mitochondria?

Answer 3

citrate

Question 4

After the removal of all sugar units from a ganglioside, what molecule remains?

Answer 4

Ceramide

Question 5

Sphingolipids are synthesized in a pathway that begins in the ER and is degraded in the ___________, but these lipids are enriched in the plasma membrane, where they perform many of their functions.

Answer 5

Lysosome

Question 6

The main lipid of chylomicrons (formed in the intestine) is ___________

Answer 6

TAG

Question 7

The apoproteins of chylomicrons (formed in the intestine) is _________

Answer 7

B-48 (A, C, E)

Question 8

The function of chylomicrons (formed in the intestine)

Answer 8

Transportation of dietary TAG to adipose and other tissues

Question 9

The main lipid of remnant chylomicrons is

Answer 9

TAG

Question 10

The apoproteins of remnant chylomicrons is

Answer 10

B-48 (A, C, E)

Question 11

The function of remnant chylomicrons is

Answer 11

Deliver remaining dietary TAG to the liver.

Question 12

How do remnant chylomicrons deliver remaining dietary TAG to the liver?

Answer 12

Exchanges TAG for CE from HDL and delivers the CE to the liver

Question 13

What is the main lipid of VLDL (formed in the liver)

Answer 13

TAG

Question 14

What is the apoprotein of VLDLs

Answer 14

B-100 (A, C, E)

Question 15

What is the function of VLDLs

Answer 15

Transport endogenously synthesized TAG to adipose tissue, skeletal muscle, and heart muscle

Question 16

How do VLDLs transport endogenously synthesized TAG?

Answer 16

Exchanges TAG for CE from HDL and delivers the CE to the liver

Question 17

What is the main lipid of IDL-VLDL remnant (formed via processing of VLDL in the circulation)

Answer 17

TAG and cholesterol

Question 18

What is the apoprotein associated with IDL-VLDL remnant (formed via processing of VLDL in the circulation)

Answer 18

B-100, E

Question 19

What is the function of IDL-VLDL remnant (formed via processing of VLDL in the circulation)

Answer 19

Delivers remaining TAG and cholesterol to the liver.

Question 20

How do IDL-VLDL remnants (formed via processing of VLDL in the circulation) deliver TAG to the liver

Answer 20

Exchanges TAG for CE from HDL. Delivers CE to the liver.

Question 21

What is the main lipid in LDLs (Formed via processing of IDL in the circulation)

Answer 21

Cholesterol

Question 22

What is the apoprotein associated with LDLs (Formed via processing of IDL in the circulation)

Answer 22

B-100

Question 23

What is the function of LDLs (Formed via processing of IDL in the circulation)

Answer 23

Deliver cholesterol to the liver and other cells, including steroidogenic cells

Question 24

What is the main lipid of HDLs (formed in the liver; some formed in the intestines)

Answer 24

Cholesterol

Question 25

What is the apoprotein associated with HDLs (formed in the liver; some formed in the intestines)

Answer 25

A's (C, E)

Question 26

What is the function of HDLs (formed in the liver; some formed in the intestines)

Answer 26

Accept cholesterol from peripheral cells, esterify it, and transport CE to the liver

Question 27

How do HDLs (formed in the liver; some formed in the intestines) get to the liver?

Answer 27

Exchange CE for TAG in VLDL, IDL, and chylomicron remnants

Question 28

How are HDLs (formed in the liver; some formed in the intestines) atheroprotective

Answer 28

Via enzymes such as paraoxonase that inhibit LDL oxidation

Question 29

HDLs (formed in the liver; some formed in the intestines) serve as a reservoir for _______

Answer 29

Circulating apoproteins (A, C, and E), which are transported to other lipoprotein particles

Question 30

What is the major lipoprotein(s) associated with B-48

Answer 30

Chylomicron

Question 31

What is the function of apoprotein B-48

Answer 31

Secretion

Question 32

What is the major lipoprotein(s) associated with B-100

Answer 32

VLDL, IDL, LDL

Question 33

What is the function of the B-100 apoprotein

Answer 33

Bind LDL receptors and VLDL secretion (vesicular trafficking pathway)

Question 34

What is the major lipoprotein(s) associated with A-1 apoprotein

Answer 34

HDL

Question 35

What is the function of the A-1 apoprotein

Answer 35

Activates LCAT (lecithin: cholesterol acyl transferase; esterifies cholesterol) and binds HDL receptor

Question 36

What is the major lipoprotein(s) associated with C-II apoprotein

Answer 36

CyM, VLDL, IDL, HDL

Question 37

What is the major function of the C-II apoprotein

Answer 37

Cofactor: activates lipoprotein lipase

Question 38

What is the major lipoprotein(s) associated with apoprotein E

Answer 38

CyM, VLDL, IDL, HDL

Question 39

What is the major function of apoprotein E?

Answer 39

Clearance via binding to LRP (LDL receptor related protein)