Question 1

What is neuroglobin,and what is its suspected role?

Accepted Answer

Neuroglobin is expressed in th

Question 2

Consider the oxygen-binding profile at three different pH values of 7.6,7.4,and 7.2.Which statement is most correct?

Accepted Answer

A)  Curve X most likely corresponds to pH 7.2. 
B)  Curve Z most likely corresponds to pH 7.6. 
C)  Hb has a higher affinity for oxygen at the pH of curve Z. 
D)  Curve Y most likely corresponds to pH 7.4. 
E)  pH has no effect on the oxygenation of hemoglobin. 
A)  Curve X most likely corresponds to pH 7.2. 
B)  Curve Z most likely corresponds to pH 7.6. 
C)  Hb has a higher affinity for oxygen at the pH of curve Z. 
D)  Curve Y most likely corresponds to pH 7.4. 
E)  pH has no effect on the oxygenation of hemoglobin.

Question 3

Describe the recurring structure called the globin fold.

Accepted Answer

Each of the four subunits of h

Question 4

The binding of 2-3-bisphosphogycerate to hemoglobin ____________ (increases,decreases)its affinity of oxygen binding.

Accepted Answer

The answer of The binding of 2-3-bisphosphogycerate to hemoglobin ____________...

Question 5

The T-state structure of deoxyhemoglobin is stabilized through ___________________ interactions between the carbamates and positively charged amino acids at the interface between αβ dimers.

Accepted Answer

The answer of The T-state structure of deoxyhemoglobin is stabilized...

Question 6

What type of binding is indicated by a sigmoidal-shaped binding curve?

Accepted Answer

A)  competitive 
B)  noncompetitive 
C)  uncooperative 
D)  cooperative 
E)  None of the answers is correct. 
A)  competitive 
B)  noncompetitive 
C)  uncooperative 
D)  cooperative 
E)  None of the answers is correct.

Question 7

Draw the oxygen-binding curve of myoglobin and that of hemoglobin.Indicate the partial pressure of oxygen in the lungs and the range of pressure in tissue.

Accepted Answer

The answer of Draw the oxygen-binding curve of myoglobin and...

Question 8

Which of the following is NOT correct concerning myoglobin?

Accepted Answer

A)  The globin chain contains an extensive α-helix structure. 
B)  The heme group is bound to the globin chain by two disulfide bonds to cysteine residues. 
C)  The iron of the heme group is in the Fe2+ oxidation state. 
D)  The diameter of the iron ion decreases upon binding to oxygen. 
E)  The function of myoglobin is oxygen storage in muscle. 
A)  The globin chain contains an extensive α-helix structure. 
B)  The heme group is bound to the globin chain by two disulfide bonds to cysteine residues. 
C)  The iron of the heme group is in the Fe2+ oxidation state. 
D)  The diameter of the iron ion decreases upon binding to oxygen. 
E)  The function of myoglobin is oxygen storage in muscle.

Question 9

Under normal conditions,the heme iron in myoglobin and hemoglobin is in the ____________ oxidation state.

Accepted Answer

The answer of Under normal conditions,the heme iron in myoglobin...

Question 10

Describe the role of 2,3-bisphosphoglycerate in the function of hemoglobin.

Accepted Answer

2,3-Bisphosphoglycerate,2,3-BPG,is a rel

Question 11

In hemoglobin,the iron of the heme is bonded to the four nitrogens of porphyrin and to the proximal ______________ residue of the globin chain.

Accepted Answer

The answer of In hemoglobin,the iron of the heme is...

Question 12

What would be the expected result of a Lys residue being replaced by a Ser residue in the BPG binding site of hemoglobin?

Accepted Answer

A)  BPG would bind tighter because of the loss of a positive charge. 
B)  BPG would bind tighter because of the gain of a positive charge. 
C)  BPG would bind less tightly because of the loss of a positive charge 
D)  BPG would bind less tightly because of the gain of a positive charge. 
E)  This substitution would have no effect on the binding of BPG. 
A)  BPG would bind tighter because of the loss of a positive charge. 
B)  BPG would bind tighter because of the gain of a positive charge. 
C)  BPG would bind less tightly because of the loss of a positive charge 
D)  BPG would bind less tightly because of the gain of a positive charge. 
E)  This substitution would have no effect on the binding of BPG.

Question 13

Which of the following is correct concerning the following equilibrium?CO2 + H2O   H2CO3

Accepted Answer

A)  An increase in the pressure of CO2 will result in a decrease of pH. 
B)  This reaction is catalyzed by carbonic anhydrase. 
C)  The H2CO3 dissociates to H+ and bicarbonate ion, HCO3-. 
D)  The majority of CO2 is transported to the lungs in the form of HCO3-. 
E)  All of the answers are correct. 
A)  An increase in the pressure of CO2 will result in a decrease of pH. 
B)  This reaction is catalyzed by carbonic anhydrase. 
C)  The H2CO3 dissociates to H+ and bicarbonate ion, HCO3-. 
D)  The majority of CO2 is transported to the lungs in the form of HCO3-. 
E)  All of the answers are correct.

Exam 7: Hemoglobin: a Portrait of a Protein in Action

What is neuroglobin,and what is its suspected role?

Consider the oxygen-binding profile at three different pH values of 7.6,7.4,and 7.2.Which statement is most correct?

Describe the recurring structure called the globin fold.

The binding of 2-3-bisphosphogycerate to hemoglobin ____________ (increases,decreases)its affinity of oxygen binding.

The T-state structure of deoxyhemoglobin is stabilized through ___________________ interactions between the carbamates and positively charged amino acids at the interface between αβ dimers.

What type of binding is indicated by a sigmoidal-shaped binding curve?

Draw the oxygen-binding curve of myoglobin and that of hemoglobin.Indicate the partial pressure of oxygen in the lungs and the range of pressure in tissue.

Which of the following is NOT correct concerning myoglobin?

Under normal conditions,the heme iron in myoglobin and hemoglobin is in the ____________ oxidation state.

Describe the role of 2,3-bisphosphoglycerate in the function of hemoglobin.

In hemoglobin,the iron of the heme is bonded to the four nitrogens of porphyrin and to the proximal ______________ residue of the globin chain.

What would be the expected result of a Lys residue being replaced by a Ser residue in the BPG binding site of hemoglobin?

Which of the following is correct concerning the following equilibrium?CO2 + H2O H2CO3

Biochemistry: An Evolving Science

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Enzymes: Basic Concepts and Kinetics

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

Oxidative Phosphorylation

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, repair, and Recombination

RNA Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

Filters

Which of the following is correct concerning the following equilibrium?CO₂ + H₂O H₂CO₃