Question 1

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)   3.5F) None of the above
G) A) and D)

Question 2

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 dehydrogenaseF) A) and B)
G) C) and D)

Question 3

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)   phosphoenolpyruvateE) B) and C)
F) A) and C)

Question 4

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.F) None of the above
G) A) and E)

Question 5

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.E) None of the above
F) All of the above

Question 6

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)   pyruvateF) A) and B)
G) A) and E) A

Question 7

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.F) B) and D)
G) None of the above

Question 8

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-CoAF) C) and D)
G) All of the above C

Question 9

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.F) A) and B)
G) C) and E)

Question 10

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.E) C) and D)
F) None of the above

Question 11

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.F) None of the above
G) A) and B)

Question 12

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)   acetoacetateF) A) and B)
G) C) and D)

Question 13

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.F) C) and E)
G) A) and B)

Question 14

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.F) A) and D)
G) B) and D)

Question 15

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.F) B) and C)
G) A) and E)

Question 16

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.E) B) and C)
F) A) and B)

Question 17

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.F) B) and D)
G) A) and E)

Question 18

Acetoacetate is NOT oxidized to C02 in

Accepted Answer

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

Question 19

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.F) A) and E)
G) A) and B)

Question 20

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 lyaseF) A) and B)
G) All of the above E

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

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Elongation of an acyl-CoA derivative in mitochondria requires

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedA

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedC

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

Correct AnswerverifiedShow Answer

Two vitamins important in beta-oxidation are

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Oxidation of acetoacetic acid to carbon dioxide and water

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

A condition which favors increased ketone body synthesis is

Correct AnswerverifiedShow Answer

A deficiency in carnitine will result in

Correct AnswerverifiedShow Answer

Acetoacetate is NOT oxidized to C02 in

Correct AnswerverifiedShow Answer

In the absence of glucose uptake in adipose tissue there is

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedE

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E