Question 1

A molecule is found to be able to diffuse across a membrane. Which of the following characteristics would best describe this molecule?

Accepted Answer

A)  hydrophilic 
B)  hydrophobic 
C)  neutral 
D)  polar 
A)  hydrophilic 
B)  hydrophobic 
C)  neutral 
D)  polar

Question 2

Predict the effect on Na+ transport through gramicidin A if the helical structure took on the conformation of a true $\alpha$-helix.

Accepted Answer

Na⁺would no longer

Question 3

Consider the following interaction between a protein and its ligand: [P] + [L]   $\harr$[PL]. If [L] = 5 mM, [P] = 3 mM, and [PL] = 2 mM, what is the dissociation constant?

Accepted Answer

A)  7.5 mM 
B)  15 mM 
C)  0.133 mM 
D)  0.4 mM 
A)  7.5 mM 
B)  15 mM 
C)  0.133 mM 
D)  0.4 mM

Question 4

What might be the effect on the transport of lactose into the cytosol of E. coli if a drug is added that allows H+ to freely pass through the inner bacterial membrane?

Accepted Answer

A)  There would be no effect. 
B)  Lactose transport would increase. 
C)  Lactose transport would cease. 
D)  Lactose would be transported out of the cytosol and into the periplasm. 
A)  There would be no effect. 
B)  Lactose transport would increase. 
C)  Lactose transport would cease. 
D)  Lactose would be transported out of the cytosol and into the periplasm.

Question 5

Which of the following is NOT considered part of the thin filament?

Accepted Answer

A)  actin 
B)  myosin 
C)  troponin 
D)  tropomyosin 
A)  actin 
B)  myosin 
C)  troponin 
D)  tropomyosin

Question 6

What role do$\beta$S-Phe85 and $\beta$S-Leu88 play in sickle cell anemia?

Accepted Answer

They interact with @#LAT-DLM&_S

Question 7

Consider a system where a passive transport channel is available for a neutral molecule X. If RTln(C2/C1) is zero, then

Accepted Answer

A)  no net transport will occur. 
B)  the molecule will move from the area where the concentration is C2 to the area where the concentration is C1. 
C)  the molecule will move from the area where the concentration is C1 to the area where the concentration is C2. 
D)  There is no way to determine if or how transport of X will occur given the information provided. 
A)  no net transport will occur. 
B)  the molecule will move from the area where the concentration is C2 to the area where the concentration is C1. 
C)  the molecule will move from the area where the concentration is C1 to the area where the concentration is C2. 
D)  There is no way to determine if or how transport of X will occur given the information provided.

Question 8

Look at the data in the figure below. If the sequence for the $\beta$ subunit was replaced with the $\beta$ subunit sequence from a patient with sickle cell disease, the number of

Accepted Answer

A)  asterisks would decrease. 
B)  colons would increase. 
C)  periods would decrease. 
D)  asterisks would increase. 
A)  asterisks would decrease. 
B)  colons would increase. 
C)  periods would decrease. 
D)  asterisks would increase.

Question 9

Fetal and adult hemoglobin have different affinities for 2,3-BPG. Predict if O2 transport from maternal cells to fetal cells will be altered from the normal rate if the$\gamma$subunit of the fetal red blood cells have a Ser143$\rightarrow$ His143 mutation. Include the term T state in your answer.

Accepted Answer

When the fetal @#LAT-DLM&subunit contains Ser143 i

Question 10

Primary active ABC transporters and P-type transporters both require

Accepted Answer

A)  a conformational change to function. 
B)  two ATP binding half-sites. 
C)  solutes that move down their concentration gradients through the transporter. 
D)  removal of inhibitory subunits to function. 
A)  a conformational change to function. 
B)  two ATP binding half-sites. 
C)  solutes that move down their concentration gradients through the transporter. 
D)  removal of inhibitory subunits to function.

Question 11

Which of the following is true of sickle cell anemia?

Accepted Answer

A)  It is a dominant genetic disease. 
B)  It is caused by a mutation in the $\alpha$-globin gene. 
C)  It is caused by an amino acid substitution in the F helix. 
D)  It results in a hemoglobin that contains a hydrophobic amino acid on the surface. 
A)  It is a dominant genetic disease. 
B)  It is caused by a mutation in the $\alpha$-globin gene. 
C)  It is caused by an amino acid substitution in the F helix. 
D)  It results in a hemoglobin that contains a hydrophobic amino acid on the surface.

Question 12

Consider an oxygen binding curve for hemoglobin at pH 7.4. The binding curve would shift __________ if the pH is reduced to 7.2.

Accepted Answer

A)  to the right 
B)  to the left 
C)  up 
D)  down 
A)  to the right 
B)  to the left 
C)  up 
D)  down

Question 13

Given the following concentrations, what is $\theta$  ? [Mb] = 0.07, [MbO2] = 0.69, [O2] = 3.5 kPa

Accepted Answer

The answer of Given the following concentrations, what is $\theta$...

Question 14

A protein displays allosteric regulation. Which of the following is true?

Accepted Answer

A)  Each subunit is either in the T state or the R state, but does not switch from one state to the other. 
B)  Each subunit can exist in more than one conformation. 
C)  When the protein binds to a positive allosteric effector, the subunits are more likely to be in the T state. 
D)  A subunit must be in the R state in order to bind ligand. 
A)  Each subunit is either in the T state or the R state, but does not switch from one state to the other. 
B)  Each subunit can exist in more than one conformation. 
C)  When the protein binds to a positive allosteric effector, the subunits are more likely to be in the T state. 
D)  A subunit must be in the R state in order to bind ligand.

Question 15

A new protein has been discovered that may be allosterically regulated. The protein is purified and analyzed by SDS-PAGE followed by staining with Coomassie blue. A single band at 42 kDa is seen on the gel. Explain how these data may or may not support the belief that the protein is an allosterically regulated protein. If they do support an allosterically regulated protein, propose the most likely model of allostery followed by the protein.

Accepted Answer

These data do not support the belief tha

Question 16

An E. coli strain is discovered that has a mutation in the gene encoding RecBCD. The mutation causes RecBCD to not function as effectively as the wild-type RecBCD. Hypothesize how the growth rate of this strain would compare with that of the wild type.

Accepted Answer

RecBCD is a genomic caretaker protein. I

Question 17

Construct a complete actin-myosin reaction cycle by placing the following steps in order, starting with Ca2+ binding to troponin:
A. ADP release empties the nucleotide binding site in myosin.
B. Pi release induces the power stroke.
C. ATP hydrolysis induces the recovery conformation.
D. ATP binding causes myosin to dissociate from actin.

Accepted Answer

Question 18

What is required for the transport of a molecule by an active transporter that is not necessary for a molecule to be transported by a passive transporter?

Accepted Answer

The answer of What is required for the transport of...

Question 19

A mutation in the $\beta$ subunit of hemoglobin is discovered that reduces the affinity of 2,3-BPG binding. Which of the following mutations is most likely to have this consequence?

Accepted Answer

A)  Val1 $\rightarrow$ Ile1 
B)  Asp99 $\rightarrow$ Glu99 
C)  Lys82 $\rightarrow$ Asp82 
D)  Glu6 $\rightarrow$ Val6 
A)  Val1 $\rightarrow$ Ile1 
B)  Asp99 $\rightarrow$ Glu99 
C)  Lys82 $\rightarrow$ Asp82 
D)  Glu6 $\rightarrow$ Val6

Question 20

Explain why ABC transporters are channels and not carriers.

Accepted Answer

ABC transporters und

A molecule is found to be able to diffuse across a membrane. Which of the following characteristics would best describe this molecule?

Predict the effect on Na⁺transport through gramicidin A if the helical structure took on the conformation of a true $\alpha$ -helix.

Consider the following interaction between a protein and its ligand: [P] + [L] $\harr$ [PL]. If [L] = 5 mM, [P] = 3 mM, and [PL] = 2 mM, what is the dissociation constant?

What might be the effect on the transport of lactose into the cytosol of E. coli if a drug is added that allows H⁺to freely pass through the inner bacterial membrane?

Which of the following is NOT considered part of the thin filament?

What role do $\beta$ _S-Phe85 and $\beta$ ^S-Leu88 play in sickle cell anemia?

Consider a system where a passive transport channel is available for a neutral molecule X. If RTln(C₂/C₁) is zero, then

Primary active ABC transporters and P-type transporters both require

Which of the following is true of sickle cell anemia?

Consider an oxygen binding curve for hemoglobin at pH 7.4. The binding curve would shift __________ if the pH is reduced to 7.2.

Given the following concentrations, what is $\theta$ ? [Mb] = 0.07, [MbO₂] = 0.69, [O₂] = 3.5 kPa

A protein displays allosteric regulation. Which of the following is true?

An E. coli strain is discovered that has a mutation in the gene encoding RecBCD. The mutation causes RecBCD to not function as effectively as the wild-type RecBCD. Hypothesize how the growth rate of this strain would compare with that of the wild type.

What is required for the transport of a molecule by an active transporter that is not necessary for a molecule to be transported by a passive transporter?

A mutation in the $\beta$ subunit of hemoglobin is discovered that reduces the affinity of 2,3-BPG binding. Which of the following mutations is most likely to have this consequence?

Explain why ABC transporters are channels and not carriers.

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

Exam 6: Protein Function

A molecule is found to be able to diffuse across a membrane. Which of the following characteristics would best describe this molecule?

Predict the effect on Na+ transport through gramicidin A if the helical structure took on the conformation of a true α\alphaα -helix.

Consider the following interaction between a protein and its ligand: [P] + [L] ↔\harr↔ [PL]. If [L] = 5 mM, [P] = 3 mM, and [PL] = 2 mM, what is the dissociation constant?

What might be the effect on the transport of lactose into the cytosol of E. coli if a drug is added that allows H+ to freely pass through the inner bacterial membrane?

Which of the following is NOT considered part of the thin filament?

What role do β\betaβ S-Phe85 and β\betaβ S-Leu88 play in sickle cell anemia?

Consider a system where a passive transport channel is available for a neutral molecule X. If RTln(C2/C1) is zero, then

Look at the data in the figure below. If the sequence for the β\betaβ subunit was replaced with the β\betaβ subunit sequence from a patient with sickle cell disease, the number of

Primary active ABC transporters and P-type transporters both require

Which of the following is true of sickle cell anemia?

Consider an oxygen binding curve for hemoglobin at pH 7.4. The binding curve would shift __________ if the pH is reduced to 7.2.

Given the following concentrations, what is θ\thetaθ ? [Mb] = 0.07, [MbO2] = 0.69, [O2] = 3.5 kPa

A protein displays allosteric regulation. Which of the following is true?

An E. coli strain is discovered that has a mutation in the gene encoding RecBCD. The mutation causes RecBCD to not function as effectively as the wild-type RecBCD. Hypothesize how the growth rate of this strain would compare with that of the wild type.

What is required for the transport of a molecule by an active transporter that is not necessary for a molecule to be transported by a passive transporter?

A mutation in the β\betaβ subunit of hemoglobin is discovered that reduces the affinity of 2,3-BPG binding. Which of the following mutations is most likely to have this consequence?

Explain why ABC transporters are channels and not carriers.

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

Predict the effect on Na⁺transport through gramicidin A if the helical structure took on the conformation of a true $\alpha$ -helix.

Consider the following interaction between a protein and its ligand: [P] + [L] $\harr$ [PL]. If [L] = 5 mM, [P] = 3 mM, and [PL] = 2 mM, what is the dissociation constant?

What might be the effect on the transport of lactose into the cytosol of E. coli if a drug is added that allows H⁺to freely pass through the inner bacterial membrane?

What role do $\beta$ _S-Phe85 and $\beta$ ^S-Leu88 play in sickle cell anemia?

Consider a system where a passive transport channel is available for a neutral molecule X. If RTln(C₂/C₁) is zero, then

Given the following concentrations, what is $\theta$ ? [Mb] = 0.07, [MbO₂] = 0.69, [O₂] = 3.5 kPa

A mutation in the $\beta$ subunit of hemoglobin is discovered that reduces the affinity of 2,3-BPG binding. Which of the following mutations is most likely to have this consequence?