Deck 10: Lipids II

Question 1

Which of the following terms describes all glycerophospholipid?

A) zwitterionic
B) amphipathic
C) nonpolar
D) amphoteric
E) none of the above

Answer 1

amphipathic

Question 2

Which of the following best describes the sequence of events for the synthesis of phosphatidylcholine?

A) phosphocholine condenses with glycerol-3-phosphate, then two fatty acids are added
B) CDP-choline reacts with a monoacylglycerol followed by fatty acid addition
C) a diacylglycerol pyrophosphate reacts with choline
D) CDP-choline reacts with a diacylglycerol
E) none of the above

Answer 2

CDP-choline reacts with a diacylglycerol

Question 3

Which of the following explains how phosphatidylserine is synthesized?

A) Serine displaces the ethanolamine from a phosphatidylethanolamine .
B) Serine reacts with a diacylglycerol pyrophosphate.
C) CDP-serine reacts with diacylglycerol.
D) Serine reacts with a CDP-diacylglycerol.
E) The ethanolamine group of phosphatidylethanolamine is carboxylated to form serine.

Answer 3

Serine displaces the ethanolamine from a phosphatidylethanolamine .

Question 4

Which two molecules are used in the synthesis of sphingosine?

A) arachidonic acid and serine
B) stearic acid and isoprene
C) palmitoyl-CoA and choline
D) linoleoyl-CoA and isoprene
E) palmitoyl-CoA and serine

Question 5

What is used to activate phosphoethanolamine prior to reaction with a diacylglycerol?

A) ATP
B) CTP
C) GTP
D) TTP
E) UTP

Question 6

To oxidize the fatty acids in a triacylglycerol, what must occur first?

A) fatty acid activation
B) lipolysis
C) transport into the mitochondria
D) oxidation of a carbon-carbon single bond to an alkene
E) none of the above

Question 7

Lipoproteins formed in the intestinal mucosal cells are called _____.

Question 8

Which of the lipoproteins is responsible for removing cholesterol from cells?

A) chylomicron
B) VLDL
C) LDL
D) HDL
E) VHDL

Question 9

Three of the key events in atherosclerosis are lipid accumulation on arterial walls, inflammation, and calcification.

Question 10

A _____ becomes a _____ through loss of cholesterol to tissue.
Dropdown 1: chylomicron, VLDL, LDL, HDL
Dropdown 2: chylomicron, VLDL, LDL, HDL

Question 11

The movement of _____ into a cell occurs by endocytosis following _____.
Dropdown 1: VLDL, LDL
Dropdown 2: binding of LDL to the LDL receptor, oxidation of the LDL particle, removal of triacylglycerols from the VLDL

Question 12

Cholesterol and other lipids are transported from tissues to the liver by _____.

Question 13

Free fatty acids bind to _____ for circulation in the bloodstream.

Question 14

Cells may take up _____ by receptor mediated endocytosis.

Question 15

______ are the lipids that are most abundant even though they are not components of membranes.

Question 16

The synthesis of triacylglycerols involves the addition of acyl groups to glycerol-3-phosphate. What is the source of the acyl groups?

A) free fatty acid
B) fatty acid attached to the acyl carrier protein
C) fatty acyl adenylate
D) acyl-carnitine
E) fatty acyl-CoA

Question 17

Which of the following best describes the order for the conversion of glycerol-3-phosphate into a triacylglycerol?

A) 1 phosphatase reaction, then 3 acyltransferase reactions
B) 1 acyltransferase reaction, 1 phosphatase reaction, then 2 more acyltransferase reactions
C) 2 acyltransferase reactions, 1 phosphatase reaction, then 1 acyltransferase reaction
D) 3 acyltransferase reactions, then 1 phosphatase reaction
E) 1 acyltransferase reaction, 1 phosphatase reaction, 1 acyltransferase reaction, 1 phosphatase reaction, then 1 acyltransferase reaction

Question 18

Which of the following commonly occurs before cholesterol is packaged into a VLDL?

A) oxidation to increase water solubility
B) esterification with a fatty acid
C) phosphorylation by ATP
D) hydration of the alkene
E) all of the above may occur

Question 19

The glycerol backbone of triacylglycerols is catabolized to _____.

Question 20

The hydrolysis of triacylglycerols stored in adipose tissue is catalyzed by the enzyme _____, often signaled by lipolytic hormones such as the catecholamines.

A) hormone-sensitive lipase
B) lipoprotein lipase
C) albumin-associated lipase
D) chylomicron lipase
E) adipocyte lipase

Question 21

A lipid raft is a(n) _____ in the lipid bilayer of a cell membrane.

A) transmembrane protein
B) integral membrane protein oriented to the intracellular side
C) integral membrane protein oriented to the extracellular side
D) region of high cholesterol and sphingolipid content
E) none of the above