Question 1

Passive membrane transporters CANNOT

Accepted Answer

A)  be small peptides. 
B)  contain $\beta$-sheets. 
C)  contain $\alpha$-helices. 
D)  contain only hydrophobic amino acids. 
A)  be small peptides. 
B)  contain $\beta$-sheets. 
C)  contain $\alpha$-helices. 
D)  contain only hydrophobic amino acids. D

Question 2

Which of the following is NOT a symptom of anemia?

Accepted Answer

A)  fatigue 
B)  shortness of breath 
C)  cognitive decline 
D)  excessive bleeding 
A)  fatigue 
B)  shortness of breath 
C)  cognitive decline 
D)  excessive bleeding D

Question 3

Which of the following curves is representative of the binding of oxygen to myoglobin?

Accepted Answer

A)  curve A 
B)  curve B 
C)  curve C 
D)  curve D 
A)  curve A 
B)  curve B 
C)  curve C 
D)  curve D A

Question 4

Which of the following statements is true of the data shown below?

Accepted Answer

A)  The binding of ligand to protein B follows the Bohr effect. 
B)  Both proteins display cooperative binding. 
C)  Protein A has a higher Kd for the ligand than protein B. 
D)  Protein B and protein A bind to the same ligand. 
A)  The binding of ligand to protein B follows the Bohr effect. 
B)  Both proteins display cooperative binding. 
C)  Protein A has a higher Kd for the ligand than protein B. 
D)  Protein B and protein A bind to the same ligand.

Question 5

Nuclear receptors are a type of

Accepted Answer

A)  metabolic enzyme. 
B)  structural protein. 
C)  transport protein. 
D)  cell signaling protein. 
A)  metabolic enzyme. 
B)  structural protein. 
C)  transport protein. 
D)  cell signaling protein.

Question 6

An effector binds to a single subunit of a multi-subunit allosteric protein. As a result, all subunits switch to the R state. This is an example of the model of allostery.

Accepted Answer

A)  concerted 
B)  homotropic 
C)  sequential 
D)  combined 
A)  concerted 
B)  homotropic 
C)  sequential 
D)  combined

Question 7

After induced changes in the structure of thin filament, myosin heads containing in the nucleotide binding site will bind with high affinity to actin subunits.

Accepted Answer

A)  ATP; ADP + Pi 
B)  ATP; Ca2+ 
C)  Ca2+; ATP 
D)  Ca2+; ADP + Pi 
A)  ATP; ADP + Pi 
B)  ATP; Ca2+ 
C)  Ca2+; ATP 
D)  Ca2+; ADP + Pi

Question 8

If a metabolic enzyme __________ the energy of activation of a reaction, the rate of product formation will _.

Accepted Answer

A)  increases; decrease 
B)  decreases; increase 
C)  increases; increase 
D)  decreases; decrease 
A)  increases; decrease 
B)  decreases; increase 
C)  increases; increase 
D)  decreases; decrease

Question 9

The E. coli maltoporin protein, but NOT the A. lividans K+ channel protein,

Accepted Answer

A)  is a homotetramer. 
B)  contains mostly $\alpha$-helices. 
C)  is a passive transporter. 
D)  uses transport dependent on interaction with amino acid side chains. 
A)  is a homotetramer. 
B)  contains mostly $\alpha$-helices. 
C)  is a passive transporter. 
D)  uses transport dependent on interaction with amino acid side chains.

Question 10

Based on the data shown below, the Kd for protein A is __________ the Kd for protein B.

Accepted Answer

A)  equal to 
B)  approximately 50% greater than 
C)  six times lower than 
D)  six times higher than 
A)  equal to 
B)  approximately 50% greater than 
C)  six times lower than 
D)  six times higher than

Question 11

Which of the following is true of this compound?

Accepted Answer

A)  It contains a ferric ion. 
B)  It is a prosthetic group. 
C)  It is found on the surface of both hemoglobin and myoglobin. 
D)  It is coordinated to hemoglobin through interactions with a proximal cysteine. 
A)  It contains a ferric ion. 
B)  It is a prosthetic group. 
C)  It is found on the surface of both hemoglobin and myoglobin. 
D)  It is coordinated to hemoglobin through interactions with a proximal cysteine.

Question 12

Vitamin C is required for prolyl hydroxylase to function. Prolyl hydroxylase enzyme activity is necessary for the proper biosynthesis of collagen. Which of the following might result from a deficiency in vitamin C?

Accepted Answer

A)  higher risk of bone breakage 
B)  a reduction in muscle contraction ability 
C)  reduced chromosomal separation during mitosis 
D)  brittle hair 
A)  higher risk of bone breakage 
B)  a reduction in muscle contraction ability 
C)  reduced chromosomal separation during mitosis 
D)  brittle hair

Question 13

Using the data shown, list the porins from the most selective to the least selective.

Accepted Answer

The answer of Using the data shown, list the porins...

Question 14

Consider the following interaction between a protein and its ligand: [P] + [L]     $\harr$ [PL]. Which equation describes the dissociation constant of this interaction?

Accepted Answer

A)  [PL] / [P][L] 
B)  [P][L] / [PL] 
C)  [PL] / [P] 
D)  [PL][P] / [L] 
A)  [PL] / [P][L] 
B)  [P][L] / [PL] 
C)  [PL] / [P] 
D)  [PL][P] / [L]

Question 15

Which of the following directly requires ATP to carry out its function?

Accepted Answer

A)  Cl -  ion channel 
B)  malate dehydrogenase 
C)  myoglobin 
D)  protein kinase A 
A)  Cl -  ion channel 
B)  malate dehydrogenase 
C)  myoglobin 
D)  protein kinase A

Question 16

Hemoglobin contains __________ $\alpha$-helices, __________ $\beta$-sheets, and globin folds.

Accepted Answer

A)  32; 4; 4 
B)  32; 0; 8 
C)  8; 8; 4 
D)  32; 0; 4 
A)  32; 4; 4 
B)  32; 0; 8 
C)  8; 8; 4 
D)  32; 0; 4

Question 17

Consider an allosteric protein that contains three identical subunits. Which of the following is true only if the protein follows the concerted model of allostery and NOT the sequential model of allostery?

Accepted Answer

A)  All three subunits exist in the R state simultaneously. 
B)  All three subunits exist in the T state simultaneously. 
C)  A ligand is bound to a single subunit and that subunit is in the T state. 
D)  No ligand is bound; two subunits are in the T state and one subunit is in the L state. 
A)  All three subunits exist in the R state simultaneously. 
B)  All three subunits exist in the T state simultaneously. 
C)  A ligand is bound to a single subunit and that subunit is in the T state. 
D)  No ligand is bound; two subunits are in the T state and one subunit is in the L state.

Question 18

An increase in sickle cell disease symptoms can occur when a person with the disease is at higher altitudes. Hypothesize how allosteric regulation at high altitudes may be related to sickle cell anemia.

Accepted Answer

At high altitudes, more 2,3-bisphosphogl

Question 19

A proposed structure of a bacterial membrane protein shows that the distance between successive amino acids in a region crossing the membrane is 3.4 Å. Recall that a typical lipid bilayer is approximately 40 Å across. Which of the following is the most likely description of the protein?

Accepted Answer

A)  The transmembrane region of the protein resembles the transmembrane region of the Ca2+-ATPase transporter protein. 
B)  The primary sequence of the transmembrane region of the protein is composed of approximately nine amino acids. 
C)  The protein contains a selectivity channel. 
D)  The protein resembles a porin. 
A)  The transmembrane region of the protein resembles the transmembrane region of the Ca2+-ATPase transporter protein. 
B)  The primary sequence of the transmembrane region of the protein is composed of approximately nine amino acids. 
C)  The protein contains a selectivity channel. 
D)  The protein resembles a porin.

Question 20

The sarcomere length of isolated heart myoblasts can be measured over time in the laboratory. The myoblasts are maintained in a buffer during the experiment. In a control experiment, Ca2+  and ATP are added to the buffer and the change in sarcomere length is analyzed. If EDTA, a chelating agent that sequesters Ca2+, was included in the buffer, the length change would be __________ compared with a control experiment without EDTA.

Accepted Answer

A)  smaller 
B)  greater 
C)  the same 
D)  There is no way to determine the result given the information provided. 
A)  smaller 
B)  greater 
C)  the same 
D)  There is no way to determine the result given the information provided.

Exam 6: Protein Function

Passive membrane transporters CANNOT

Which of the following is NOT a symptom of anemia?

Which of the following curves is representative of the binding of oxygen to myoglobin?

Which of the following statements is true of the data shown below?

Nuclear receptors are a type of

An effector binds to a single subunit of a multi-subunit allosteric protein. As a result, all subunits switch to the R state. This is an example of the model of allostery.

After induced changes in the structure of thin filament, myosin heads containing in the nucleotide binding site will bind with high affinity to actin subunits.

If a metabolic enzyme __________ the energy of activation of a reaction, the rate of product formation will _.

The E. coli maltoporin protein, but NOT the A. lividans K+ channel protein,

Based on the data shown below, the Kd for protein A is __________ the Kd for protein B.

Which of the following is true of this compound?

Vitamin C is required for prolyl hydroxylase to function. Prolyl hydroxylase enzyme activity is necessary for the proper biosynthesis of collagen. Which of the following might result from a deficiency in vitamin C?

Using the data shown, list the porins from the most selective to the least selective.

Consider the following interaction between a protein and its ligand: [P] + [L] ↔\harr↔ [PL]. Which equation describes the dissociation constant of this interaction?

Which of the following directly requires ATP to carry out its function?

Hemoglobin contains __________ α\alphaα -helices, __________ β\betaβ -sheets, and globin folds.

Consider an allosteric protein that contains three identical subunits. Which of the following is true only if the protein follows the concerted model of allostery and NOT the sequential model of allostery?

An increase in sickle cell disease symptoms can occur when a person with the disease is at higher altitudes. Hypothesize how allosteric regulation at high altitudes may be related to sickle cell anemia.

A proposed structure of a bacterial membrane protein shows that the distance between successive amino acids in a region crossing the membrane is 3.4 Å. Recall that a typical lipid bilayer is approximately 40 Å across. Which of the following is the most likely description of the protein?

Principles of Biochemistry

Physical Biochemistry: Energy Conversion, Water, and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

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

Amino Acid 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

The E. coli maltoporin protein, but NOT the A. lividans K⁺channel protein,

Based on the data shown below, the K_d for protein A is __________ the K_d for protein B.

Consider the following interaction between a protein and its ligand: [P] + [L] $\harr$ [PL]. Which equation describes the dissociation constant of this interaction?

Hemoglobin contains $\alpha$ -helices, $\beta$ -sheets, and globin folds.