Question 1

Which enzyme or process requires the presence of acetyl-CoA in the cytosol?

Accepted Answer

A)  pyruvate dehydrogenase 
B)  PEP (phosphoenolpyruvate) carboxykinase 
C)  synthesis of ketone bodies 
D)  reversal of the citrate synthase reaction 
E)  ATP: citrate lyase 
A)  pyruvate dehydrogenase 
B)  PEP (phosphoenolpyruvate) carboxykinase 
C)  synthesis of ketone bodies 
D)  reversal of the citrate synthase reaction 
E)  ATP: citrate lyase E

Question 2

The formation of acetoacetic acid from acetyl-CoA involves which of the following compounds as an intermediate?

Accepted Answer

A)  malonic acid 
B)  mevalonic acid 
C)  3-hydroxy-3-methylglutaryl-CoA 
D)  3-hydroxybutyryl-CoA 
E)  succinyl-CoA 
A)  malonic acid 
B)  mevalonic acid 
C)  3-hydroxy-3-methylglutaryl-CoA 
D)  3-hydroxybutyryl-CoA 
E)  succinyl-CoA C

Question 3

Which of the following is the best positive effector of acetyl coenzyme A carboxylase?

Accepted Answer

A)  citrate 
B)  oxaloacetate 
C)  malonyl coenzyme A 
D)  ADP 
E)  pyruvate 
A)  citrate 
B)  oxaloacetate 
C)  malonyl coenzyme A 
D)  ADP 
E)  pyruvate A

Question 4

In mitochondria, the electron donor for the last reductive step in the elongation of the carbon chain of a fatty acid is

Accepted Answer

A)  NADH. 
B)  FADH2. 
C)  FMNH2. 
D)  NADPH. 
E)  coenzyme Q-2H. 
A)  NADH. 
B)  FADH2. 
C)  FMNH2. 
D)  NADPH. 
E)  coenzyme Q-2H.

Question 5

Which one of the following factors is considered to be rate limiting in the oxidation of palmitic acid in liver?

Accepted Answer

A)  Rate of formation of palmitoyl-CoA. 
B)  The concentration of cytosolic carnitine. 
C)  The activity of carnitine-palmitoyl-acyl transferase-I. 
D)  The activity of palmitoyl-CoA dehydrogenase. 
E)  The concentration of acetoacetyl-CoA. 
A)  Rate of formation of palmitoyl-CoA. 
B)  The concentration of cytosolic carnitine. 
C)  The activity of carnitine-palmitoyl-acyl transferase-I. 
D)  The activity of palmitoyl-CoA dehydrogenase. 
E)  The concentration of acetoacetyl-CoA.

Question 6

A condition which favors increased ketone body synthesis is

Accepted Answer

A)  increased glycogenolysis in skeletal muscle. 
B)  increased fatty acid synthesis in liver. 
C)  increased lipolysis in adipose tissue. 
D)  decreased gluconeogenesis in liver. 
A)  increased glycogenolysis in skeletal muscle. 
B)  increased fatty acid synthesis in liver. 
C)  increased lipolysis in adipose tissue. 
D)  decreased gluconeogenesis in liver.

Question 7

All of the following are involved in the conversion of pyruvate to a long chain saturated fatty acid EXCEPT

Accepted Answer

A)  malonyl-CoA. 
B)  NADPH. 
C)  carbon dioxide. 
D)  acyl carrier protein. 
E)  cyclic AMP. 
A)  malonyl-CoA. 
B)  NADPH. 
C)  carbon dioxide. 
D)  acyl carrier protein. 
E)  cyclic AMP.

Question 8

Elongation of an acyl-CoA derivative in mitochondria requires

Accepted Answer

A)  NADH + H+ and acetyl-CoA. 
B)  NADH + H+ and malonyl-CoA. 
C)  NADPH + H+ and acetyl-CoA. 
D)  NADPH + H+ and malonyl-CoA. 
E)  NADPH + H+, malonyl-CoA and ATP. 
A)  NADH + H+ and acetyl-CoA. 
B)  NADH + H+ and malonyl-CoA. 
C)  NADPH + H+ and acetyl-CoA. 
D)  NADPH + H+ and malonyl-CoA. 
E)  NADPH + H+, malonyl-CoA and ATP.

Question 9

Two vitamins important in beta-oxidation are

Accepted Answer

A)  riboflavin and niacin. 
B)  pantothenic acid and cholecalciferol. 
C)  coenzyme A and thiamine. 
D)  riboflavin and ascorbic acid. 
A)  riboflavin and niacin. 
B)  pantothenic acid and cholecalciferol. 
C)  coenzyme A and thiamine. 
D)  riboflavin and ascorbic acid.

Question 10

Acetoacetate is NOT oxidized to C02 in

Accepted Answer

A)  brain. 
B)  skeletal muscle. 
C)  heart. 
D)  liver. 
E)  nervous tissue. 
A)  brain. 
B)  skeletal muscle. 
C)  heart. 
D)  liver. 
E)  nervous tissue.

Question 11

Oxidation of acetoacetic acid to carbon dioxide and water

Accepted Answer

A)  by the liver mitochondria follows its direct reaction with CoA-SH. 
B)  requires an investment of two equivalents of ATP. 
C)  requires transfer to the CoA residue of succinyl-CoA. 
D)  takes place preferentially in the brain. 
E)  yields 38 equivalents of ATP. 
A)  by the liver mitochondria follows its direct reaction with CoA-SH. 
B)  requires an investment of two equivalents of ATP. 
C)  requires transfer to the CoA residue of succinyl-CoA. 
D)  takes place preferentially in the brain. 
E)  yields 38 equivalents of ATP.

Question 12

In the absence of glucose uptake in adipose tissue there is

Accepted Answer

A)  net synthesis of triglycerides because glycerol accumulates. 
B)  net synthesis of triglycerides because fatty acids accumulate. 
C)  release of fatty acids because fatty acid oxidation is inhibited. 
D)  a decrease in triglyceride synthesis because there is a deficiency of glycerol phosphate. 
E)  None of the other answers is correct. 
A)  net synthesis of triglycerides because glycerol accumulates. 
B)  net synthesis of triglycerides because fatty acids accumulate. 
C)  release of fatty acids because fatty acid oxidation is inhibited. 
D)  a decrease in triglyceride synthesis because there is a deficiency of glycerol phosphate. 
E)  None of the other answers is correct.

Question 13

In mitochondrial oxidation of arachidonate to two carbon units all the following enzymes are used EXCEPT

Accepted Answer

A)  enoyl hydratase. 
B)  acyl CoA dehydrogenase. 
C)  enoyl CoA isomerase. 
D)  lipoxygenase 
E)  B-hydroxy acyl CoA dehydrogenase. 
A)  enoyl hydratase. 
B)  acyl CoA dehydrogenase. 
C)  enoyl CoA isomerase. 
D)  lipoxygenase 
E)  B-hydroxy acyl CoA dehydrogenase.

Question 14

The beta-oxidation of oleic acid (delta-9) as opposed to palmitic acid requires the addition of which of the following enzymes?

Accepted Answer

A)  enoyl-CoA hydratase 
B)  L-beta-ketoacyl-CoA thiolase 
C)  enoyl-CoA isomerase 
D)  acyl-CoA dehydrogenase 
E)  L-beta hydroxyacyl-CoA dehydrogenase 
A)  enoyl-CoA hydratase 
B)  L-beta-ketoacyl-CoA thiolase 
C)  enoyl-CoA isomerase 
D)  acyl-CoA dehydrogenase 
E)  L-beta hydroxyacyl-CoA dehydrogenase

Question 15

Acetyl-CoA for de novo fatty acid biosynthesis is formed by the energy-dependent cleavage of

Accepted Answer

A)  pyruvate 
B)  oxaloacetate 
C)  citrate 
D)  alpha-ketoglutarate 
E)  acetoacetate 
A)  pyruvate 
B)  oxaloacetate 
C)  citrate 
D)  alpha-ketoglutarate 
E)  acetoacetate

Question 16

A deficiency in carnitine will result in

Accepted Answer

A)  a decreased synthesis of phospholipids in the endoplasmic reticulum. 
B)  a decreased level of fatty acyl CoA in the cytoplasm. 
C)  a decreased synthesis of fatty acyl adenylate in the mitochondria. 
D)  an increased level of fatty acid in the cytoplasm. 
E)  an increased level of fatty acyl pantetheine in the mitochondria. 
A)  a decreased synthesis of phospholipids in the endoplasmic reticulum. 
B)  a decreased level of fatty acyl CoA in the cytoplasm. 
C)  a decreased synthesis of fatty acyl adenylate in the mitochondria. 
D)  an increased level of fatty acid in the cytoplasm. 
E)  an increased level of fatty acyl pantetheine in the mitochondria.

Question 17

Glucose metabolism is necessary in adipose tissue to supply which of the following for the formation of triglycerides?

Accepted Answer

A)  ribose 5-phosphate 
B)  succinyl-CoA 
C)  alpha-glycerol phosphate 
D)  phosphoenolpyruvate 
A)  ribose 5-phosphate 
B)  succinyl-CoA 
C)  alpha-glycerol phosphate 
D)  phosphoenolpyruvate

Question 18

A fatty acid 10 carbons long can theoretically form how many moles of acetoacetate from the 2 carbon units directly generated during its breakdown?

Accepted Answer

A)  1.5 
B)  2.0 
C)  2.5 
D)  3.0 
E)  3.5 
A)  1.5 
B)  2.0 
C)  2.5 
D)  3.0 
E)  3.5

Question 19

The conversion of n moles of acetyl-CoA to 1 mole of palmitoyl-CoA (C16:0) requires

Accepted Answer

A)  0 moles of ATP. 
B)  5 moles of ATP. 
C)  7 moles of ATP. 
D)  8 moles of ATP. 
A)  0 moles of ATP. 
B)  5 moles of ATP. 
C)  7 moles of ATP. 
D)  8 moles of ATP.

Question 20

Physiological conditions which promote the synthesis of ketone bodies would also promote the

Accepted Answer

A)  oxidation of fatty acids in erythrocytes. 
B)  oxidation of glucose in adipose tissue. 
C)  synthesis of amino acids in liver. 
D)  synthesis of fatty acids in liver. 
E)  synthesis of glucose in liver. 
A)  oxidation of fatty acids in erythrocytes. 
B)  oxidation of glucose in adipose tissue. 
C)  synthesis of amino acids in liver. 
D)  synthesis of fatty acids in liver. 
E)  synthesis of glucose in liver.

Exam 17: Lipid Metabolism I: Synthesis, Storage, and Utilization of Fatty Acids and Triacylglycerols

Which enzyme or process requires the presence of acetyl-CoA in the cytosol?

The formation of acetoacetic acid from acetyl-CoA involves which of the following compounds as an intermediate?

Which of the following is the best positive effector of acetyl coenzyme A carboxylase?

In mitochondria, the electron donor for the last reductive step in the elongation of the carbon chain of a fatty acid is

Which one of the following factors is considered to be rate limiting in the oxidation of palmitic acid in liver?

A condition which favors increased ketone body synthesis is

All of the following are involved in the conversion of pyruvate to a long chain saturated fatty acid EXCEPT

Elongation of an acyl-CoA derivative in mitochondria requires

Two vitamins important in beta-oxidation are

Acetoacetate is NOT oxidized to C02 in

Oxidation of acetoacetic acid to carbon dioxide and water

In the absence of glucose uptake in adipose tissue there is

In mitochondrial oxidation of arachidonate to two carbon units all the following enzymes are used EXCEPT

The beta-oxidation of oleic acid (delta-9) as opposed to palmitic acid requires the addition of which of the following enzymes?

Acetyl-CoA for de novo fatty acid biosynthesis is formed by the energy-dependent cleavage of

A deficiency in carnitine will result in

Glucose metabolism is necessary in adipose tissue to supply which of the following for the formation of triglycerides?

A fatty acid 10 carbons long can theoretically form how many moles of acetoacetate from the 2 carbon units directly generated during its breakdown?

The conversion of n moles of acetyl-CoA to 1 mole of palmitoyl-CoA (C16:0) requires

Physiological conditions which promote the synthesis of ketone bodies would also promote the

Eukaryotic Cell Structure

DNA and RNA: Composition and Structure

Protein I: Composition and Structure

DNA Replication, Recombination, and Repair

RNA: Transcription and Rna Processing

Protein Synthesis: Translation and Posttranslational Modifications

Recombinant Dna and Biotechnology

Regulation of Gene Expression

Protein II: Structure-Function Relationships in Protein Families

Enzymes: Classification, Kinetics, and Control

The Cytochromes P450 and Nitric Oxide Synthases

Biological Membranes: Structure and Membrane Transport

Fundamentals of Signal Transduction

Bioenergetics and Oxidative Metabolism

Carbohydrate Metabolism I: Major Metabolic Pathways and Their Control

Carbohydrate Metabolism II: Special Pathways and Glycoconjugates

Lipid Metabolism II: Pathways of Metabolism of Special Lipids

Amino Acid Metabolism

Purine and Pyrimidine Nucleotide Metabolism

Metabolic Interrelationships

Biochemistry of Hormones

Molecular Cell Biology

Cell Cycle, Programmed Cell Death, and Cancer

Digestion and Absorption of Basic Nutritional Constituents

Digestion and Absorption of Basic Nutritional Constituents

Principles of Nutrition I and II

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