Question 1

Which of the following is(are)advantages to the constant degradation and reformation of proteins?

Accepted Answer

A) Nutrients can be stored as proteins, which can be used during periods of metabolic need. 
B) Damaged proteins are eliminated so they do not accumulate. 
C) Metabolism can be efficiently regulated by the synthesis and degradation of enzymes. 
D) All of the above are advantages. 
E) None of the above is an advantage. 
A) Nutrients can be stored as proteins, which can be used during periods of metabolic need. 
B) Damaged proteins are eliminated so they do not accumulate. 
C) Metabolism can be efficiently regulated by the synthesis and degradation of enzymes. 
D) All of the above are advantages. 
E) None of the above is an advantage.

Question 2

The presence of SGOT and SGPT in the serum indicate potential

Accepted Answer

A) starvation and brain tissue damage. 
B) inflammation. 
C) heart attack or liver damage. 
D) lung or breast cancer. 
E) none of the above 
A) starvation and brain tissue damage. 
B) inflammation. 
C) heart attack or liver damage. 
D) lung or breast cancer. 
E) none of the above

Question 3

The pictured compound, glutamate-5-semialdehyde, is an intermediate in the biosynthesis of which of the following amino acids?

Accepted Answer

A) histidine 
B) arginine 
C) methionine 
D) threonine 
E) More than one of the above is made from this intermediate. 
A) histidine 
B) arginine 
C) methionine 
D) threonine 
E) More than one of the above is made from this intermediate.

Question 4

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-The amino acid ______ has been thought to act as a transfer system for NH3, safely allowing the toxic molecule to be transported from the liver to the kidneys.

Accepted Answer

A) ribosomes 
B) jaundice 
C) channeling 
D) 26S proteasome 
E) glutamine synthetase
F)alanine
G)glutamate
H)vitamin B6
I)anammox
J)glutamine transferase
K)THF
L)autotroph
M)vitamin D
N)lysosomes
O)diazotrophs 
A) ribosomes 
B) jaundice 
C) channeling 
D) 26S proteasome 
E) glutamine synthetase
F)alanine
G)glutamate
H)vitamin B6
I)anammox
J)glutamine transferase
K)THF
L)autotroph
M)vitamin D
N)lysosomes
O)diazotrophs

Question 5

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-The enzyme ______ is critical to regulating nitrogen metabolism.

Accepted Answer

A) ribosomes 
B) jaundice 
C) channeling 
D) 26S proteasome 
E) glutamine synthetase
F)alanine
G)glutamate
H)vitamin B6
I)anammox
J)glutamine transferase
K)THF
L)autotroph
M)vitamin D
N)lysosomes
O)diazotrophs 
A) ribosomes 
B) jaundice 
C) channeling 
D) 26S proteasome 
E) glutamine synthetase
F)alanine
G)glutamate
H)vitamin B6
I)anammox
J)glutamine transferase
K)THF
L)autotroph
M)vitamin D
N)lysosomes
O)diazotrophs

Question 6

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-Infants who cannot properly degrade bilirubin develop ______.

Accepted Answer

A) ribosomes 
B) jaundice 
C) channeling 
D) 26S proteasome 
E) glutamine synthetase
F)alanine
G)glutamate
H)vitamin B6
I)anammox
J)glutamine transferase
K)THF
L)autotroph
M)vitamin D
N)lysosomes
O)diazotrophs 
A) ribosomes 
B) jaundice 
C) channeling 
D) 26S proteasome 
E) glutamine synthetase
F)alanine
G)glutamate
H)vitamin B6
I)anammox
J)glutamine transferase
K)THF
L)autotroph
M)vitamin D
N)lysosomes
O)diazotrophs

Question 7

Which of the following describes the steps required prior to ATP-dependent degradation of proteins?
I.Ubiquitin is transferred to cysteine on a ubiquitin-conjugating enzyme.
II.The protein is linked to at least four tandemly linked ubiquitin units.
III.Activated ubiquitin is transferred to a lysine of the previously bound protein.
IV.Ubiquitin is attached via a thioester to a unbiquitin-activiating enzyme.

Accepted Answer

A) I, II, III, IV 
B) IV, I, III, II 
C) II, I, III, IV 
D) IV, II, I, III 
E) IV, II, III, I 
A) I, II, III, IV 
B) IV, I, III, II 
C) II, I, III, IV 
D) IV, II, I, III 
E) IV, II, III, I

Question 8

In which cellular location listed below does the following reaction take place? 
ornithine + carbamoyl-phosphate → citrulline

Accepted Answer

A) cytosol 
B) mitochondrial matrix 
C) lysosome 
D) A or B 
E) none of the above 
A) cytosol 
B) mitochondrial matrix 
C) lysosome 
D) A or B 
E) none of the above

Question 9

Which of the following amino acid breakdown reactions would be catalyzed by an aminotransferase?

Accepted Answer

A) Threonine $\rarr$ Acetyl CoA 
B) Alanine $\rarr$ Pyruvate 
C) Asparagine $\rarr$ Aspartate 
D) Homocysteine $\rarr$ Methionone 
E) HMG-CoA $\rarr$ Acetoacetate 
A) Threonine $\rarr$ Acetyl CoA 
B) Alanine $\rarr$ Pyruvate 
C) Asparagine $\rarr$ Aspartate 
D) Homocysteine $\rarr$ Methionone 
E) HMG-CoA $\rarr$ Acetoacetate

Question 10

Which of the following require a cyclic carbohydrate precursor for synthesis?
I.histidine
II.alanine
III.arginine
IV.tyrosine

Accepted Answer

A) I, II 
B) II only 
C) I, III 
D) I , IV 
E) II, IV 
A) I, II 
B) II only 
C) I, III 
D) I , IV 
E) II, IV

Question 11

The lifetime of a protein in cells actively involved in metabolism

Accepted Answer

A) is longer in eukaryotes than in prokaryotes. 
B) ranges from months to years. 
C) is independent of the function and activity of the protein. 
D) can change in response to changes in metabolic hormone levels. 
E) none of the above 
A) is longer in eukaryotes than in prokaryotes. 
B) ranges from months to years. 
C) is independent of the function and activity of the protein. 
D) can change in response to changes in metabolic hormone levels. 
E) none of the above

Question 12

Which of the following are essential amino acids for adult humans?

Accepted Answer

A) Arg, His, Gly, Try 
B) Met, Lys, His, Val 
C) His, Leu, Tyr, Ala 
D) Met, Gly, Thr, Ser 
E) Ala, Arg, Cys, Ser 
A) Arg, His, Gly, Try 
B) Met, Lys, His, Val 
C) His, Leu, Tyr, Ala 
D) Met, Gly, Thr, Ser 
E) Ala, Arg, Cys, Ser

Question 13

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-A phenomenon in which intermediates are directly transferred from one active site to another is ______.

Accepted Answer

A) ribosomes 
B) jaundice 
C) channeling 
D) 26S proteasome 
E) glutamine synthetase
F)alanine
G)glutamate
H)vitamin B6
I)anammox
J)glutamine transferase
K)THF
L)autotroph
M)vitamin D
N)lysosomes
O)diazotrophs 
A) ribosomes 
B) jaundice 
C) channeling 
D) 26S proteasome 
E) glutamine synthetase
F)alanine
G)glutamate
H)vitamin B6
I)anammox
J)glutamine transferase
K)THF
L)autotroph
M)vitamin D
N)lysosomes
O)diazotrophs

Question 14

Which of the following statements about maple syrup urine disease is FALSE?
I.It is caused by a genetic deficiency in the enzyme BCKDH.
II.The disease is fatal unless promptly treated.
III.There is a buildup of the branched-chain $\alpha$-keto acids.
IV.Patients with the disease excrete urine that smells like maple syrup.

Accepted Answer

A) I only 
B) II only 
C) I, III 
D) III, IV 
E) All of the statements are true. 
A) I only 
B) II only 
C) I, III 
D) III, IV 
E) All of the statements are true.

Question 15

What species are combined to produce carbamoyl phosphate?

Accepted Answer

A) NH3 , PO43−, HCO3− 
B) NH4+, PO43−, Ac-CoA, releasing CoA-SH 
C) glycine & inorganic phosphate, releasing CO2 
D) acetate & NH4+, releasing CO2 
E) alanine & inorganic phosphate, releasing acetate 
A) NH3 , PO43−, HCO3− 
B) NH4+, PO43−, Ac-CoA, releasing CoA-SH 
C) glycine & inorganic phosphate, releasing CO2 
D) acetate & NH4+, releasing CO2 
E) alanine & inorganic phosphate, releasing acetate

Question 16

A mutation in GDH of patients with HI/HA (hypoglycemia/hyperammonemia)results in a decrease in allosteric control of GDH via GTP.Which of the following will be observed in the patients?

Accepted Answer

A) an increase in ammonia 
B) an increase in glutamate 
C) an increase in NADH 
D) A and B 
E) A and C 
A) an increase in ammonia 
B) an increase in glutamate 
C) an increase in NADH 
D) A and B 
E) A and C

Question 17

Matching 
Choose the correct answer from the list. Not all the answers will be used.
-Organisms known as _____ can fix nitrogen into metabolically useful molecules.

Accepted Answer

A) ribosomes 
B) jaundice 
C) channeling 
D) 26S proteasome 
E) glutamine synthetase
F)alanine
G)glutamate
H)vitamin B6
I)anammox
J)glutamine transferase
K)THF
L)autotroph
M)vitamin D
N)lysosomes
O)diazotrophs 
A) ribosomes 
B) jaundice 
C) channeling 
D) 26S proteasome 
E) glutamine synthetase
F)alanine
G)glutamate
H)vitamin B6
I)anammox
J)glutamine transferase
K)THF
L)autotroph
M)vitamin D
N)lysosomes
O)diazotrophs

Question 18

Which of the following amino acids is NOT synthesized from aspartate?

Accepted Answer

A) threonine 
B) methionine 
C) lysine 
D) cysteine 
E) All of the above are synthesized from aspartic acid. 
A) threonine 
B) methionine 
C) lysine 
D) cysteine 
E) All of the above are synthesized from aspartic acid.

Question 19

The total cost of nitrogen reduction is ____ and ___ transferred electrons.

Accepted Answer

A) 8 ATP; 4 
B) 12 ATP; 8 
C) 12 ATP; 6 
D) 16 ATP; 8 
E) 16 ATP; 6 
A) 8 ATP; 4 
B) 12 ATP; 8 
C) 12 ATP; 6 
D) 16 ATP; 8 
E) 16 ATP; 6

Question 20

Which of the following reaction sequences could result in glucose synthesis?

Accepted Answer

A) fumarate $\rarr$ arginine $\rarr$ urea 
B) fumarate $\rarr$ malate $\rarr$ oxaloacetate 
C) citrulline $\rarr$ urea $\rarr$aspartate 
D) urea $\rarr$ arginine $\rarr$ ornithine 
E) none of the above 
A) fumarate $\rarr$ arginine $\rarr$ urea 
B) fumarate $\rarr$ malate $\rarr$ oxaloacetate 
C) citrulline $\rarr$ urea $\rarr$aspartate 
D) urea $\rarr$ arginine $\rarr$ ornithine 
E) none of the above

Exam 21: Amino Acid Metabolism

Which of the following is(are)advantages to the constant degradation and reformation of proteins?

The presence of SGOT and SGPT in the serum indicate potential

The pictured compound, glutamate-5-semialdehyde, is an intermediate in the biosynthesis of which of the following amino acids?

Matching Choose the correct answer from the list. Not all the answers will be used. -The amino acid ______ has been thought to act as a transfer system for NH3, safely allowing the toxic molecule to be transported from the liver to the kidneys.

Matching Choose the correct answer from the list. Not all the answers will be used. -The enzyme ______ is critical to regulating nitrogen metabolism.

Matching Choose the correct answer from the list. Not all the answers will be used. -Infants who cannot properly degrade bilirubin develop ______.

In which cellular location listed below does the following reaction take place? ornithine + carbamoyl-phosphate → citrulline

Which of the following amino acid breakdown reactions would be catalyzed by an aminotransferase?

Which of the following require a cyclic carbohydrate precursor for synthesis? I.histidine II.alanine III.arginine IV.tyrosine

The lifetime of a protein in cells actively involved in metabolism

Which of the following are essential amino acids for adult humans?

Matching Choose the correct answer from the list. Not all the answers will be used. -A phenomenon in which intermediates are directly transferred from one active site to another is ______.

What species are combined to produce carbamoyl phosphate?

A mutation in GDH of patients with HI/HA (hypoglycemia/hyperammonemia)results in a decrease in allosteric control of GDH via GTP.Which of the following will be observed in the patients?

Matching Choose the correct answer from the list. Not all the answers will be used. -Organisms known as _____ can fix nitrogen into metabolically useful molecules.

Which of the following amino acids is NOT synthesized from aspartate?

The total cost of nitrogen reduction is ____ and ___ transferred electrons.

Which of the following reaction sequences could result in glucose synthesis?

Introduction to the Chemistry of Life

Water

Nucleotides, Nucleic Acids, and Genetic Information

Amino Acids

Proteins: Primary Structure

Proteins: Three-Dimensional Structure

Protein Function Part I: Myoglobin and Hemoglobin

Carbohydrates

Lipids and Biological Membranes

Membrane Transport

Enzyme Catalysis

Enzyme Kinetics, Inhibition and Control

Biochemical Signaling

Introduction to Metabolism

Glycogen Metabolism and Gluconeogenesis

Glucose Catabolism

Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Mammalian Fuel Metabolism: Integration and Regulation

Nucleotide Metabolism

Nucleic Acid Structure

Dna Replication, Repair and Recombination

Transcription and Rna Processing

Translation

Regulation of Gene Expression

Filters

Matching Choose the correct answer from the list. Not all the answers will be used. -The amino acid ______ has been thought to act as a transfer system for NH₃, safely allowing the toxic molecule to be transported from the liver to the kidneys.

The total cost of nitrogen reduction is __ and _ transferred electrons.