Question 1

Given the following data for myoglobin and O2 concentrations,what is   
[Mb] = 0.07 mM,[MbO2] = 0.69 mM,[O2] = 3.5 kPa.

Accepted Answer

0.9

Question 2

What is the clinical term for reduced O2 transport efficiency from the lungs to the tissues,arising from altered hemoglobin function or reduced numbers of red blood cells per unit of blood? Provide an example of a specific type of anemia that is caused by a single point mutation.

Accepted Answer

Anemia; sickle cell anemia

Question 3

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

Accepted Answer

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

Question 4

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 5

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 6

Gramicidin A is involved in the __________ transport of __________ charged ions.

Accepted Answer

A)  active; positively 
B)  active; negatively 
C)  passive; positively 
D)  passive; negatively 
A)  active; positively 
B)  active; negatively 
C)  passive; positively 
D)  passive; negatively

Question 7

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 8

Oxygen binding is monitored for a solution of hemoglobin.During the experiment,the curve changes from sigmoidal to hyperbolic.Which of the following may be the reason for the change?

Accepted Answer

A)  A positive allosteric effector was added. 
B)  A negative allosteric effector was added. 
C)  The protein dissociated into individual subunits. 
D)  The protein denatured. 
A)  A positive allosteric effector was added. 
B)  A negative allosteric effector was added. 
C)  The protein dissociated into individual subunits. 
D)  The protein denatured.

Question 9

Which of the following is NOT a characteristic of an enzyme active site?

Accepted Answer

A)  It has a three-dimensional shape. 
B)  It plays a role in increasing the energy of activation of the reaction being catalyzed. 
C)  It is a unique chemical environment. 
D)  It is where the substrate of the reaction can be found. 
A)  It has a three-dimensional shape. 
B)  It plays a role in increasing the energy of activation of the reaction being catalyzed. 
C)  It is a unique chemical environment. 
D)  It is where the substrate of the reaction can be found.

Question 10

The E.coli maltoporin protein is a homotrimeric porin complex.A related protein is found in another bacterial species that does not form trimers but rather functions as a monomer.A comparison of the amino acid composition of a maltoporin subunit and the new porin showed similar ratios of hydrophobic/hydrophilic amino acids for the two proteins.Explain how this can be the case.

Accepted Answer

The porins are embedded in the membrane.

Question 11

Which is true of the K+ channel but NOT of an aquaporin?

Accepted Answer

A)  Selectivity is achieved through interactions with backbone NH groups. 
B)  It contains  -helices. 
C)  It is an active transporter. 
D)  Selectivity is assisted through inverted  -helix dipoles. 
A)  Selectivity is achieved through interactions with backbone NH groups. 
B)  It contains  -helices. 
C)  It is an active transporter. 
D)  Selectivity is assisted through inverted  -helix dipoles.

Question 12

Complete the following bacterial ABC transporter protein process:
1.Binding of substrate carrier protein induces a conformational change to expose the substrate binding site.
2.ATP hydrolysis causes a conformational change that releases substrate.
3.

Accepted Answer

Release of ADP + P_i a

Question 13

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 14

Which of the following statements is true for hemoglobin but NOT myoglobin?

Accepted Answer

A)  The tertiary structure is made up of a globin fold. 
B)  The surface of its tertiary structure contains many hydrophobic amino acids. 
C)  It contains a proximal histidine that coordinates the heme group. 
D)  It contains a single carboxyl-terminal amino acid. 
A)  The tertiary structure is made up of a globin fold. 
B)  The surface of its tertiary structure contains many hydrophobic amino acids. 
C)  It contains a proximal histidine that coordinates the heme group. 
D)  It contains a single carboxyl-terminal amino acid.

Question 15

Explain why ABC transporters are channels and not carriers.

Accepted Answer

ABC transporters und

Question 16

The transport system shown below is a(n)

Accepted Answer

A)  secondary active symporter. 
B)  primary active transporter. 
C)  secondary active antiporter. 
D)  ABC transporter. 
A)  secondary active symporter. 
B)  primary active transporter. 
C)  secondary active antiporter. 
D)  ABC transporter.

Question 17

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

Accepted Answer

They interact with @#IMG-DLM&_TB6697_11

Question 18

Phospholamban contains two phosphorylation sites,Ser16 and Thr17.Compare and contrast what directs the phosphorylation at each site and the resulting changes in activity of phospholamban.

Accepted Answer

Ser16 is phosphorylated by protein kinas

Question 19

Look at the data in the figure below.One amino acid location is indicated by an arrow.Why is the amino acid at that location invariant among the three sequences?

Accepted Answer

This is the F8 histidine.It is

Question 20

Passive transporter proteins allow molecules to move across a membrane in response to

Accepted Answer

A)  chemical gradients. 
B)  ADP/ATP ratio. 
C)  ATP/ADP ratio. 
D)  activated signal transduction pathways. 
A)  chemical gradients. 
B)  ADP/ATP ratio. 
C)  ATP/ADP ratio. 
D)  activated signal transduction pathways.

Exam 6: Protein Function

Given the following data for myoglobin and O2 concentrations,what is [Mb] = 0.07 mM,[MbO2] = 0.69 mM,[O2] = 3.5 kPa.

What is the clinical term for reduced O2 transport efficiency from the lungs to the tissues,arising from altered hemoglobin function or reduced numbers of red blood cells per unit of blood? Provide an example of a specific type of anemia that is caused by a single point mutation.

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

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

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?

Gramicidin A is involved in the __________ transport of __________ charged ions.

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?

Oxygen binding is monitored for a solution of hemoglobin.During the experiment,the curve changes from sigmoidal to hyperbolic.Which of the following may be the reason for the change?

Which of the following is NOT a characteristic of an enzyme active site?

Which is true of the K+ channel but NOT of an aquaporin?

Complete the following bacterial ABC transporter protein process: 1.Binding of substrate carrier protein induces a conformational change to expose the substrate binding site. 2.ATP hydrolysis causes a conformational change that releases substrate. 3.

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?

Which of the following statements is true for hemoglobin but NOT myoglobin?

Explain why ABC transporters are channels and not carriers.

The transport system shown below is a(n)

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

Phospholamban contains two phosphorylation sites,Ser16 and Thr17.Compare and contrast what directs the phosphorylation at each site and the resulting changes in activity of phospholamban.

Look at the data in the figure below.One amino acid location is indicated by an arrow.Why is the amino acid at that location invariant among the three sequences?

Passive transporter proteins allow molecules to move across a membrane in response to

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

Given the following data for myoglobin and O₂ concentrations,what is [Mb] = 0.07 mM,[MbO₂] = 0.69 mM,[O₂] = 3.5 kPa.

What is the clinical term for reduced O₂ transport efficiency from the lungs to the tissues,arising from altered hemoglobin function or reduced numbers of red blood cells per unit of blood? Provide an example of a specific type of anemia that is caused by a single point mutation.

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

Gramicidin A is involved in the transport of charged ions.

Which is true of the K⁺ channel but NOT of an aquaporin?

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