Question 1

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 A

Question 2

Matching
Choose the correct answer from the list.Not all the answers will be used.

-The cofactor ______ is used to transfer C1 units such as methyl,formyl,and methenyl groups.

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 K

Question 3

Matching
Choose the correct answer from the list.Not all the answers will be used.

-Aminotransferases utilize a coenzyme synthesized from ______.

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 H

Question 4

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 5

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 6

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 7

In which cellular location listed below does the following reaction take place?
Arginine → urea + ornithine

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 8

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 9

Which of the following statements about tryptophan synthase is FALSE?

Accepted Answer

A) Indole can pass between active sites via a channel in the enzyme. 
B) Tryptophan synthase catalyzes two distinct reaction steps to form tryptophan. 
C) The enzyme is a tetramer of four identical subunits. 
D) The enzyme has two states,an "open" and "closed",to ensure that bound indole is not lost to solvent. 
E) The indole group is produced following release of glyceraldehyde-3-phosphate from the indole-glycerol-3-phosphate. 
A) Indole can pass between active sites via a channel in the enzyme. 
B) Tryptophan synthase catalyzes two distinct reaction steps to form tryptophan. 
C) The enzyme is a tetramer of four identical subunits. 
D) The enzyme has two states,an "open" and "closed",to ensure that bound indole is not lost to solvent. 
E) The indole group is produced following release of glyceraldehyde-3-phosphate from the indole-glycerol-3-phosphate.

Question 10

What are KFERQ proteins?
(I)Proteins that contain the KFERQ pentapeptide sequence (or a similar sequence).
(II)Proteins that are selectively degraded in tissues that atrophy after a prolonged fast (starvation).
(III)A special set of enzymes that are activated in response to starvation.

Accepted Answer

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

Question 11

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 12

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 13

Which enzyme catalyses a reaction via an enzyme-bound adenylated intermediate?

Accepted Answer

A) glutamine synthetase 
B) argininosuccinate synthetase 
C) carbamoyl phosphate synthetase I 
D) Ac-CoA decarboxylase 
E) arginase 
A) glutamine synthetase 
B) argininosuccinate synthetase 
C) carbamoyl phosphate synthetase I 
D) Ac-CoA decarboxylase 
E) arginase

Question 14

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 15

Matching
Choose the correct answer from the list.Not all the answers will be used.

-ATP-dependent degradation of ubiquitinated proteins is mediated by ______.

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 16

The neurotransmitters,dopamine,epinephrine,and norepinephrine are synthesized from the amino acid

Accepted Answer

A) tryptophan 
B) tyrosine 
C) glutamate 
D) aspartate 
E) lysine 
A) tryptophan 
B) tyrosine 
C) glutamate 
D) aspartate 
E) lysine

Question 17

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 18

The synthesis of which of the following uses an aminotransferase in the first step of the synthesis?

Accepted Answer

A) glutamine 
B) proline 
C) serine 
D) valine 
E) all of the above 
A) glutamine 
B) proline 
C) serine 
D) valine 
E) all of the above

Question 19

Heme biosynthesis

Accepted Answer

A) requires that synthesis of the protoporphryin ring occur in the mitochondria due to difficulties in transporting large molecule. 
B) is inhibited in lead poisoning. 
C) can be completed using enzymes from the cytosol. 
D) A and B 
E) A,B,and C 
A) requires that synthesis of the protoporphryin ring occur in the mitochondria due to difficulties in transporting large molecule. 
B) is inhibited in lead poisoning. 
C) can be completed using enzymes from the cytosol. 
D) A and B 
E) A,B,and C

Question 20

Individuals with an alanine to valine mutation in N5,N10 - methylenetetrahydrofolate reductase (MTHFR)
(I)typically have higher levels of homocysteine.
(II)have increased risk for cardiovascular disease.
(III)typically have increased incidence of oxidative damage to the walls of blood vessels.
(IV)are at increased risk,if female,of giving birth to a child with a neural tube defect.

Accepted Answer

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

Exam 21: Amino Acid Metabolism

What species are combined to produce carbamoyl phosphate?

Matching Choose the correct answer from the list.Not all the answers will be used. -The cofactor ______ is used to transfer C1 units such as methyl,formyl,and methenyl groups.

Matching Choose the correct answer from the list.Not all the answers will be used. -Aminotransferases utilize a coenzyme synthesized from ______.

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

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

In which cellular location listed below does the following reaction take place? Arginine → urea + ornithine

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

Which of the following statements about tryptophan synthase is FALSE?

What are KFERQ proteins? (I)Proteins that contain the KFERQ pentapeptide sequence (or a similar sequence). (II)Proteins that are selectively degraded in tissues that atrophy after a prolonged fast (starvation). (III)A special set of enzymes that are activated in response to starvation.

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

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

Which enzyme catalyses a reaction via an enzyme-bound adenylated intermediate?

Matching Choose the correct answer from the list.Not all the answers will be used. -ATP-dependent degradation of ubiquitinated proteins is mediated by ______.

The neurotransmitters,dopamine,epinephrine,and norepinephrine are synthesized from the amino acid

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 synthesis of which of the following uses an aminotransferase in the first step of the synthesis?

Heme biosynthesis

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

Glucose Catabolism

Glycogen Metabolism and Gluconeogenesis

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

Protein Synthesis

Regulation of Gene Expression

Filters

Matching Choose the correct answer from the list.Not all the answers will be used. -The cofactor ______ is used to transfer C₁ units such as methyl,formyl,and methenyl groups.

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

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.