Question 1

Which of the following is not an example of a passive-mediated transporter?

Accepted Answer

A) aquaporins 
B) the Kv ion channel 
C) GLUT1 
D) lactose permease 
E) none of the above 
A) aquaporins 
B) the Kv ion channel 
C) GLUT1 
D) lactose permease 
E) none of the above

Question 2

In the body hydrogen ions produced from the reaction of carbonic anhydrase are transported into the lumen of the stomach via an ATP utilizing proton pump.The removal of hydrogen ions drives formation of bicarbonate ions and a concentration gradient is formed.Bicarbonate is transported out at the same time that chloride ions are transferred in.Based on this information,which of the following is FALSE?

Accepted Answer

A) The pump driving the driving the hydrogen ions into the lumen must undergo a conformational change. 
B) The pump driving bicarbonate out and chloride in must be an antiport system. 
C) The pump driving bicarbonate out and chloride in must require ATP directly. 
D) The bicarbonate-chloride pump requires ATP indirectly. 
E) The bicarbonate-chloride pump must require activity of the proton pump. 
A) The pump driving the driving the hydrogen ions into the lumen must undergo a conformational change. 
B) The pump driving bicarbonate out and chloride in must be an antiport system. 
C) The pump driving bicarbonate out and chloride in must require ATP directly. 
D) The bicarbonate-chloride pump requires ATP indirectly. 
E) The bicarbonate-chloride pump must require activity of the proton pump.

Question 3

D-Glucose and D-mannitol are similarly soluble,but D-glucose is transported through the erythrocyte membrane four times as rapidly as D-mannitol.What is the most likely explanation?

Accepted Answer

A) D-glucose undergoes simple diffusion more rapidly than mannitol because glucose is less polar. 
B) D-glucose and D-mannitol enter the erythrocyte via an ion-gated channel. 
C) D-glucose and D-mannitol are transported via a system that distinguishes the two sugars. 
D) D-glucose flux through the membrane is linear whereas D-mannitol flux is described by a hyperbolic curve. 
E) None of the above provides the explanation. 
A) D-glucose undergoes simple diffusion more rapidly than mannitol because glucose is less polar. 
B) D-glucose and D-mannitol enter the erythrocyte via an ion-gated channel. 
C) D-glucose and D-mannitol are transported via a system that distinguishes the two sugars. 
D) D-glucose flux through the membrane is linear whereas D-mannitol flux is described by a hyperbolic curve. 
E) None of the above provides the explanation.

Question 4

A pore that simultaneously transports two different molecules in different directions is called

Accepted Answer

A) a symport. 
B) a uniport . 
C) a gap junction. 
D) an equilibrium channel. 
E) an antiport. 
A) a symport. 
B) a uniport . 
C) a gap junction. 
D) an equilibrium channel. 
E) an antiport.

Question 5

Matching

-KcsA is an example of a ______ ionophore.

Accepted Answer

A)  Porins 
B)  gap junctions 
C)  symport 
D)  active 
E)  ion channel
F) secondary active 
G) channel-forming 
H) carrier ionophores
I) passive-mediated
J) uniport
K) simple diffusion
L) anti-ion transport 
A)  Porins 
B)  gap junctions 
C)  symport 
D)  active 
E)  ion channel
F) secondary active 
G) channel-forming 
H) carrier ionophores
I) passive-mediated
J) uniport
K) simple diffusion
L) anti-ion transport

Question 6

What type of gradient is required for efficient lactose transport in E.coli?

Accepted Answer

A) sodium 
B) potassium 
C) proton 
D) magnesium 
E) calcium 
A) sodium 
B) potassium 
C) proton 
D) magnesium 
E) calcium

Question 7

Which of the following correctly describes the reason for the specificity of valinomycin?

Accepted Answer

A) The K+ ion is the only ion small enough to fit through the ion channel. 
B) The K+ radius is the ideal size for a large binding affinity because it minimizes steric strain and potential for degrees of rotation. 
C) It selectively binds to the entrance of the transporter which is lined with negatively charged amino acids. 
D) All of the above describe the specificity. 
E) None of the above describe the specificity. 
A) The K+ ion is the only ion small enough to fit through the ion channel. 
B) The K+ radius is the ideal size for a large binding affinity because it minimizes steric strain and potential for degrees of rotation. 
C) It selectively binds to the entrance of the transporter which is lined with negatively charged amino acids. 
D) All of the above describe the specificity. 
E) None of the above describe the specificity.

Question 8

Which of the transporters listed below differs from the others?

Accepted Answer

A) (Na+-K+)-ATPase 
B) Na+-glucose transporter 
C) lactose permease 
D) KcsA 
E) Ca2+-ATPase 
A) (Na+-K+)-ATPase 
B) Na+-glucose transporter 
C) lactose permease 
D) KcsA 
E) Ca2+-ATPase

Question 9

Which of the following compounds would cross a biological membrane most readily by nonmediated diffusion?

Accepted Answer

A) water 
B) acetone 
C) hexane 
D) acetic acid 
E) methanol 
A) water 
B) acetone 
C) hexane 
D) acetic acid 
E) methanol

Which of the following is not an example of a passive-mediated transporter?

D-Glucose and D-mannitol are similarly soluble,but D-glucose is transported through the erythrocyte membrane four times as rapidly as D-mannitol.What is the most likely explanation?

A pore that simultaneously transports two different molecules in different directions is called

Matching -KcsA is an example of a ______ ionophore.

What type of gradient is required for efficient lactose transport in E.coli?

Which of the following correctly describes the reason for the specificity of valinomycin?

Which of the transporters listed below differs from the others?

Which of the following compounds would cross a biological membrane most readily by nonmediated diffusion?

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

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

Amino Acid 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

Exam 10: Membrane Transport

Which of the following is not an example of a passive-mediated transporter?

D-Glucose and D-mannitol are similarly soluble,but D-glucose is transported through the erythrocyte membrane four times as rapidly as D-mannitol.What is the most likely explanation?

A pore that simultaneously transports two different molecules in different directions is called

Matching -KcsA is an example of a ______ ionophore.

What type of gradient is required for efficient lactose transport in E.coli?

Which of the following correctly describes the reason for the specificity of valinomycin?

Which of the transporters listed below differs from the others?

Which of the following compounds would cross a biological membrane most readily by nonmediated diffusion?

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

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

Amino Acid 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