Question 1

A person unable to produce new melanocytes is likely to have

Accepted Answer

A)  black hair. 
B)  red hair. 
C)  gray hair. 
D)  hair loss. 
A)  black hair. 
B)  red hair. 
C)  gray hair. 
D)  hair loss.

Question 2

Diseases affecting heme biosynthesis as a result of deficiencies in the heme biosynthetic pathway are called

Accepted Answer

A)  porphyrias. 
B)  albinism. 
C)  shikimate. 
D)  alkaptonuria. 
A)  porphyrias. 
B)  albinism. 
C)  shikimate. 
D)  alkaptonuria.

Question 3

In the production of urea, the carbon atom comes from

Accepted Answer

A)  water. 
B)  carbamoyl phosphate. 
C)  aspartate. 
D)  the citrate cycle. 
A)  water. 
B)  carbamoyl phosphate. 
C)  aspartate. 
D)  the citrate cycle.

Question 4

What nitrogen source is used to produce carbamoyl phosphate?

Accepted Answer

A)  alanine 
B)  urea 
C)  ammonia 
D)  glutamine 
A)  alanine 
B)  urea 
C)  ammonia 
D)  glutamine

Question 5

The two mechanisms to regulate protein ubiquitination are biochemical changes to

Accepted Answer

A)  target proteins and E1 ligases. 
B)  E1 and E2 ligases. 
C)  target proteins and E3 ligases. 
D)  the E2-ubiquitin-E3 complex. 
A)  target proteins and E1 ligases. 
B)  E1 and E2 ligases. 
C)  target proteins and E3 ligases. 
D)  the E2-ubiquitin-E3 complex.

Question 6

Arginine, leucine, and lysine are all essential amino acids. This means that they are

Accepted Answer

A)  only available from a person's diet. 
B)  produced from other intermediates. 
C)  not needed for a body to function. 
D)  the main intermediates to the urea cycle. 
A)  only available from a person's diet. 
B)  produced from other intermediates. 
C)  not needed for a body to function. 
D)  the main intermediates to the urea cycle.

Question 7

Jaundice is indicative of what process working inefficiently?

Accepted Answer

A)  heme synthesis 
B)  bilirubin removal from blood 
C)  urea synthesis 
D)  amino acid degradation 
A)  heme synthesis 
B)  bilirubin removal from blood 
C)  urea synthesis 
D)  amino acid degradation

Question 8

What would the products be for the reaction below?

Accepted Answer

A)  "$\alpha$-keto acid and glutamate" 
B)  "oxaloacetate and glutamate" 
C)  "pyruvate and glutamate" 
D)  "histidine and glutamate" 
A)  "$\alpha$-keto acid and glutamate" 
B)  "oxaloacetate and glutamate" 
C)  "pyruvate and glutamate" 
D)  "histidine and glutamate"

Question 9

Summarize the role of the glycine in the biosynthesis of heme, tyrosine for epinephrine and pheomelanins, and arginine for nitric oxide.

Accepted Answer

Glycine is required for heme biosynthesi

Question 10

The 10 amino acids that animals need to take in through their diet are called the __________ amino acids.

Accepted Answer

A)  common 
B)  essential 
C)  optional 
D)  degradation 
A)  common 
B)  essential 
C)  optional 
D)  degradation

Question 11

Glucogenic amino acids give rise to which molecule?

Accepted Answer

A)  pyruvate 
B)  urea 
C)  ketone bodies 
D)  glucose 
A)  pyruvate 
B)  urea 
C)  ketone bodies 
D)  glucose

Question 12

A person who has alkaptonuria is easily diagnosed from his or her black urine. What causes the black color?

Accepted Answer

A)  oxidation of phenylalanine 
B)  oxidation of homogentisate 
C)  reduction of acetoacetyl-CoA 
D)  dehydration 
A)  oxidation of phenylalanine 
B)  oxidation of homogentisate 
C)  reduction of acetoacetyl-CoA 
D)  dehydration

Question 13

Because nitrogenase is inhibited by oxygen, under what conditions can the enzyme operate to reduce N2?

Accepted Answer

A)  aerobic conditions 
B)  anaerobic conditions 
C)  high pressure 
D)  high temperature 
A)  aerobic conditions 
B)  anaerobic conditions 
C)  high pressure 
D)  high temperature

Question 14

How is carbamoyl phosphate synthetase I allosterically regulated in the urea cycle?

Accepted Answer

This key reaction in urea synthesis is a

Question 15

How many different forms of pyridoxal phosphate are observed in the aminotransferase reaction?

Accepted Answer

A)  7 
B)  6 
C)  5 
D)  4 
A)  7 
B)  6 
C)  5 
D)  4

Question 16

In the absence of ATP for glutamine synthetase to use, what would happen to the concentration of glutamine in the cell?

Accepted Answer

A)  increase 
B)  decrease 
C)  no change 
D)  Not enough information is given. 
A)  increase 
B)  decrease 
C)  no change 
D)  Not enough information is given.

Question 17

What is a possible outcome to the urea cycle if the cell is unable to produce enough aspartate?

Accepted Answer

A)  Flux would be accelerated through the cycle. 
B)  There would be a buildup of citrulline. 
C)  There would be a buildup of urea. 
D)  The cycle would maintain equilibrium. 
A)  Flux would be accelerated through the cycle. 
B)  There would be a buildup of citrulline. 
C)  There would be a buildup of urea. 
D)  The cycle would maintain equilibrium.

Question 18

The process of nitrogen fixation reduces N2 to

Accepted Answer

A)  NAD+. 
B)  nitrate. 
C)  ammonia. 
D)  nitrite. 
A)  NAD+. 
B)  nitrate. 
C)  ammonia. 
D)  nitrite.

Question 19

To increase the efficiency of the nitrogenase reaction, some plants have symbionts. The plant increases the efficiency of the reaction by providing , whereas bacteria provide(s) .

Accepted Answer

A)  fumerate and malate; additional NH3 
B)  fumerate and malate; ATP 
C)  ATP; amino acids 
D)  NADH; ATP 
A)  fumerate and malate; additional NH3 
B)  fumerate and malate; ATP 
C)  ATP; amino acids 
D)  NADH; ATP

Question 20

Why does carbamoyl phosphate synthetase I require two equivalents of ATP?

Accepted Answer

The reaction mechanism for carbamoyl pho

Exam 17: Amino Acid Metabolism

A person unable to produce new melanocytes is likely to have

Diseases affecting heme biosynthesis as a result of deficiencies in the heme biosynthetic pathway are called

In the production of urea, the carbon atom comes from

What nitrogen source is used to produce carbamoyl phosphate?

The two mechanisms to regulate protein ubiquitination are biochemical changes to

Arginine, leucine, and lysine are all essential amino acids. This means that they are

Jaundice is indicative of what process working inefficiently?

What would the products be for the reaction below?

Summarize the role of the glycine in the biosynthesis of heme, tyrosine for epinephrine and pheomelanins, and arginine for nitric oxide.

The 10 amino acids that animals need to take in through their diet are called the __________ amino acids.

Glucogenic amino acids give rise to which molecule?

A person who has alkaptonuria is easily diagnosed from his or her black urine. What causes the black color?

Because nitrogenase is inhibited by oxygen, under what conditions can the enzyme operate to reduce N2?

How is carbamoyl phosphate synthetase I allosterically regulated in the urea cycle?

How many different forms of pyridoxal phosphate are observed in the aminotransferase reaction?

In the absence of ATP for glutamine synthetase to use, what would happen to the concentration of glutamine in the cell?

What is a possible outcome to the urea cycle if the cell is unable to produce enough aspartate?

The process of nitrogen fixation reduces N2 to

To increase the efficiency of the nitrogenase reaction, some plants have symbionts. The plant increases the efficiency of the reaction by providing , whereas bacteria provide(s) .

Why does carbamoyl phosphate synthetase I require two equivalents of ATP?

Principles of Biochemistry

Physical Biochemistry: Energy Conversion, Water, and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Carbohydrate Metabolism

Lipid Structure and Function

Lipid Metabolism

Nucleotide Metabolism

Metabolic Integration

DNA Replication, Repair, and Recombination

RNA Synthesis, Processing, and Gene Silencing

Protein Synthesis, Posttranslational Modification, and Transport

Gene Regulation

Filters

Because nitrogenase is inhibited by oxygen, under what conditions can the enzyme operate to reduce N₂?

The process of nitrogen fixation reduces N₂ to