Chapter 22. Fatty Acid Metabolism

Question 1

an enzyme of the glyoxylate cycle that catalyzes the formation of oxaloacetate from glyoxylate and acetyl CoA.

Answer 1

Malonyl CoA

Question 2

refers to acetoacetate, β-hydroxybutyrate, and acetone, produced when acetyl CoA is diverted from the citric acid cycle to formation of acetoacetyl CoA in liver; subsequent reactions generate the three compounds, known as ketone bodies.

Answer 2

Ketone body

Question 3

carbon compounds containing 20 carbon atoms, such as prostaglandins. Eicosanoids often act as local hormones.

Answer 3

Eicosanoid

Question 4

a zwitterionic compound formed from lysine that acts as a carrier of long-chain fatty acids from the cytosol to the mitochondrial matrix.

Answer 4

Carnitine

Question 5

the enzyme that catalyzes the ATP-dependent synthesis of malonyl CoA from acetyl CoA and carbon dioxide, the committed step in fatty acid synthesis.

Answer 5

Acetyl CoA carboxylase

Question 6

small membrane-bound organelles that are present in most eukaryotes and play a role in detoxification, synthesis of plasmalogens and bile salts, and β-oxidation of long-chain fatty acids.

Answer 6

Peroxisome

Question 7

a bacterial polypeptide which is linked to phosphopantetheine and which acts as a carrier of the growing fatty acyl chain during fatty acid biosynthesis.

Answer 7

Acyl carrier protein (ACP)

Question 8

A class of short-lived signal molecules that are 20-carbon fatty acids containing a fivemembered ring.

Answer 8

Prostaglandin

Question 9

the enzyme system that catalyzes the synthesis of saturated long-chain fatty acids from acetyl CoA, malonyl CoA, and NADPH. In bacteria, the constituent enzymes of the synthase complex can be dissociated when cell extracts are prepared; in mammals, all constituent enzyme activities in fatty acid synthase are part of the same polypeptide.

Answer 9

Fatty acid synthase

Question 10

a mixed anhydride in which the carboxyl group of a molecule is linked to the phosphoryl group of AMP; formation of acyl adenylates is a means of activating carboxyl groups in biochemical reactions, such as the formation of fatty acyl CoA molecules from a free fatty acid and coenzyme A.

Answer 10

Acyl adenylate

Question 11

a 20:4 fatty acid derived from linoleate that is a major precursor to several classes of signal molecules, including prostaglandins.

Answer 11

Arachidonate

Question 12

a protein kinase, conserved among eukaryotes, that is activated upon binding of AMP and inhibited by ATP. Consequently, it functions as a cellular fuel gauge, inhibiting certain process by phosphorylating key enzymes when the energy supply is low.

Answer 12

AMP-dependent protein kinase (AMPK)

Question 13

Droplets of triacylglycerol surrounded by a monolayer of phospholipids and numerous proteins required for triacylglycerol metabolism

Answer 13

lipid droplet

Question 14

The enzyme which cleaves citrate after it is transported to the cytoplasm, yielding acetyl CoA and oxaloacetate.

Answer 14

ATP-citrate lyase

Question 15

A class of compounds useful as drugs that are synthesized by megasynthases.

Answer 15

polyketide

Question 16

glycerols that have fatty acyl chains esterified to each of their hydroxyl groups; storage form of fats; also known as neutral fats or triglycerides

Answer 16

Triacylglycerol (neutral fat, triglyceride)

Question 17

a prosthetic group, consisting of a cobalt atom, a corrin ring, and deoxyadenosine, that plays a role in intramolecular rearrangements, methylations, and reductions of ribonucleotides to deoxyribonucleotides.

Answer 17

Vitamin B 12 (cobalamin)

Question 18

The series of reactions that take place during oxidation at the β carbon atom that convert fatty acids into acetyl CoA units

Answer 18

β-oxidation pathway