Question 1

Phosphatidate is synthesized from glycerol-3-phosphate.Which statement is correct about the enzymes and the order of esterification reactions in the synthesis?

Accepted Answer

A) Esterification at C-2 by 1-acylglycerol-3-phosphate acyltransferase followed by esterification at C-1 by glycerol-3-phosphate acyltransferase. 
B) Esterification at C-1 by 1-acylglycerol-3-phosphate acyltransferase followed by esterification at C-2 by glycerol-3-phosphate acyltransferase. 
C) Esterification at C-2 by glycerol-3-phosphate acyltransferase followed by esterification at C-1 by 1-acylglycerol-3-phosphate acyltransferase. 
D) Esterification at C-1 by glycerol-3-phosphate acyltransferase followed by esterification at C-2 by 1-acylglycerol-3-phosphate acyltransferase. 
A) Esterification at C-2 by 1-acylglycerol-3-phosphate acyltransferase followed by esterification at C-1 by glycerol-3-phosphate acyltransferase. 
B) Esterification at C-1 by 1-acylglycerol-3-phosphate acyltransferase followed by esterification at C-2 by glycerol-3-phosphate acyltransferase. 
C) Esterification at C-2 by glycerol-3-phosphate acyltransferase followed by esterification at C-1 by 1-acylglycerol-3-phosphate acyltransferase. 
D) Esterification at C-1 by glycerol-3-phosphate acyltransferase followed by esterification at C-2 by 1-acylglycerol-3-phosphate acyltransferase.

Question 2

There are two forms of COX activity.COX-1 regulates stomach mucin,protecting the stomach lining;COX-2 promotes inflammation,pain and fever.Newer anti-inflammatory drugs for arthritic patients would inhibit

Accepted Answer

A) COX-1. 
B) COX-2. 
C) Both COX-1 and COX-2. 
D) Arachidonate synthesis. 
A) COX-1. 
B) COX-2. 
C) Both COX-1 and COX-2. 
D) Arachidonate synthesis.

Question 3

How many QH2 and NADH are produced from a saturated fatty acid by one round of the β-oxidation pathway?

Accepted Answer

A) 1 each. 
B) 1 QH2 and 2 NADH. 
C) 2 each. 
D) 2 QH2 and 1 NADH. 
A) 1 each. 
B) 1 QH2 and 2 NADH. 
C) 2 each. 
D) 2 QH2 and 1 NADH.

Question 4

Linoleate is required for human diet because it is necessary for the synthesis of arachidonate and eicosanoids.

Accepted Answer

A) True 
 B)False

Question 5

Which of the following is not a stage of fatty acid synthesis?

Accepted Answer

A) Condensation of precursors. 
B) Rearrangement. 
C) Reduction. 
D) Dehydration. 
A) Condensation of precursors. 
B) Rearrangement. 
C) Reduction. 
D) Dehydration.

Question 6

To oxidize the fatty acid molecule shown below,what enzyme(s)is(are)needed in addition to the enzymes needed for β-oxidation?

Accepted Answer

A) Enoyl-CoA isomerase only. 
B) 2,4-dienoyl-CoA reductase only. 
C) Both enoyl-CoA isomerase and 2,4-dienoyl-CoA reductase. 
D) No additional enzymes are needed besides the normal ones for β-oxidation. 
A) Enoyl-CoA isomerase only. 
B) 2,4-dienoyl-CoA reductase only. 
C) Both enoyl-CoA isomerase and 2,4-dienoyl-CoA reductase. 
D) No additional enzymes are needed besides the normal ones for β-oxidation.

Question 7

What is the major role of phospholipase A2?

Accepted Answer

A) To cleave the phosphate group from phospholipids. 
B) To phosphorylate the enzyme enoyl-CoA. 
C) To hydrolyze an ester bond in glycerophospholipids to form lysophosphoglyceride. 
D) To transport glycerophospholipids in the blood. 
A) To cleave the phosphate group from phospholipids. 
B) To phosphorylate the enzyme enoyl-CoA. 
C) To hydrolyze an ester bond in glycerophospholipids to form lysophosphoglyceride. 
D) To transport glycerophospholipids in the blood.

Question 8

Chylomicrons are found in high concentrations in the blood only during fasting when lipids from adipose tissue are mobilized.

Accepted Answer

A) True 
 B)False

Question 9

An increase in glucagon levels activates the enzyme which catalyzes malonyl CoA synthesis in the liver.

Accepted Answer

A) True 
 B)False

Question 10

A trifunctional enzyme for β-oxidation containing sites for activities for an entire pathway is an example of

Accepted Answer

A) cooperative control. 
B) metabolic channeling. 
C) energy loss. 
D) separation of biosynthetic and degradation pathways. 
A) cooperative control. 
B) metabolic channeling. 
C) energy loss. 
D) separation of biosynthetic and degradation pathways.

Question 11

The elongation of fatty acids is a repetition of three reactions adding carbons from ________ after each cycle until completion.

Accepted Answer

A) malonyl CoA 
B) malonyl ACP 
C) acetyl CoA 
D) acetyl ACP 
A) malonyl CoA 
B) malonyl ACP 
C) acetyl CoA 
D) acetyl ACP

Question 12

Which of the following is a true statement for fatty acid oxidation?

Accepted Answer

A) It occurs in the cytosol. 
B) Oxidation requires a three carbon substrate,which transfers a two-carbon unit to the chain. 
C) Both NADH and QH2 are produced. 
D) None of the above. 
A) It occurs in the cytosol. 
B) Oxidation requires a three carbon substrate,which transfers a two-carbon unit to the chain. 
C) Both NADH and QH2 are produced. 
D) None of the above.

Question 13

In eukaryotes the enzyme complex called fatty acid synthase is responsible for the assembly of the fatty acid chain.

Accepted Answer

A) True 
 B)False

Question 14

The largest lipoproteins are the ________.

Accepted Answer

A) chylomicrons 
B) VLDLs 
C) LDLs 
D) HDLs 
A) chylomicrons 
B) VLDLs 
C) LDLs 
D) HDLs

Question 15

Which bonds of the triacylglycerol shown are hydrolyzed by pancreatic lipase?

Accepted Answer

A) The carbon-carbon bonds between atoms 1,2 and 3. 
B) The ester bond at carbon 2 only. 
C) The bonds between the carbonyl carbons 4 and 6 and the first carbon of the hydrocarbon chains. 
D) The ester bonds at carbons 1 and 3 only. 
A) The carbon-carbon bonds between atoms 1,2 and 3. 
B) The ester bond at carbon 2 only. 
C) The bonds between the carbonyl carbons 4 and 6 and the first carbon of the hydrocarbon chains. 
D) The ester bonds at carbons 1 and 3 only.

Question 16

Triacylglycerols are more efficient to store than carbohydrates because their hydrophobicity allows them to be stored in adipose cells without large amounts of bound water molecules.

Accepted Answer

A) True 
 B)False

Question 17

The first step in fatty acid synthesis is the formation of ________ from acetyl CoA and carbon dioxide.

Accepted Answer

A) acetyl ACP 
B) acetoacetyl ACP 
C) malonyl CoA 
D) acetoacetyl CoA 
A) acetyl ACP 
B) acetoacetyl ACP 
C) malonyl CoA 
D) acetoacetyl CoA

Question 18

Ketone bodies may be produced during periods of starvation.Which statement is true about ketone bodies?

Accepted Answer

A) They are toxic by-products from the degradation of muscle tissue. 
B) They serve as substitutes for glucose to fuel the brain. 
C) They are used to replenish oxaloacetate in the citric acid cycle. 
D) The reduction of ketone bodies keeps the electron transport chain going. 
A) They are toxic by-products from the degradation of muscle tissue. 
B) They serve as substitutes for glucose to fuel the brain. 
C) They are used to replenish oxaloacetate in the citric acid cycle. 
D) The reduction of ketone bodies keeps the electron transport chain going.

Question 19

The conversion of the fatty acid palmitate (C16)to carbon dioxide via β-oxidation,the citric acid cycle and oxidative phosphorylation yield approximately ________ ATP equivalents.

Accepted Answer

A) 3 
B) 32 
C) 106 
D) 800 
A) 3 
B) 32 
C) 106 
D) 800

Question 20

S-adenosylmethionine methylates phosphatidylethanolamine to form phosphatidylcholine.

Accepted Answer

A) True 
 B)False

Exam 16: Lipid Metabolism

Phosphatidate is synthesized from glycerol-3-phosphate.Which statement is correct about the enzymes and the order of esterification reactions in the synthesis?

There are two forms of COX activity.COX-1 regulates stomach mucin,protecting the stomach lining;COX-2 promotes inflammation,pain and fever.Newer anti-inflammatory drugs for arthritic patients would inhibit

How many QH2 and NADH are produced from a saturated fatty acid by one round of the β-oxidation pathway?

Linoleate is required for human diet because it is necessary for the synthesis of arachidonate and eicosanoids.

Which of the following is not a stage of fatty acid synthesis?

To oxidize the fatty acid molecule shown below,what enzyme(s)is(are)needed in addition to the enzymes needed for β-oxidation?

What is the major role of phospholipase A2?

Chylomicrons are found in high concentrations in the blood only during fasting when lipids from adipose tissue are mobilized.

An increase in glucagon levels activates the enzyme which catalyzes malonyl CoA synthesis in the liver.

A trifunctional enzyme for β-oxidation containing sites for activities for an entire pathway is an example of

The elongation of fatty acids is a repetition of three reactions adding carbons from ________ after each cycle until completion.

Which of the following is a true statement for fatty acid oxidation?

In eukaryotes the enzyme complex called fatty acid synthase is responsible for the assembly of the fatty acid chain.

The largest lipoproteins are the ________.

Which bonds of the triacylglycerol shown are hydrolyzed by pancreatic lipase?

Triacylglycerols are more efficient to store than carbohydrates because their hydrophobicity allows them to be stored in adipose cells without large amounts of bound water molecules.

The first step in fatty acid synthesis is the formation of ________ from acetyl CoA and carbon dioxide.

Ketone bodies may be produced during periods of starvation.Which statement is true about ketone bodies?

The conversion of the fatty acid palmitate (C16)to carbon dioxide via β-oxidation,the citric acid cycle and oxidative phosphorylation yield approximately ________ ATP equivalents.

S-adenosylmethionine methylates phosphatidylethanolamine to form phosphatidylcholine.

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Photosynthesis

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

Filters

How many QH₂ and NADH are produced from a saturated fatty acid by one round of the β-oxidation pathway?