Question 1

Which gas does NOT bind to the heme Fe+2 ion in myoglobin?

Accepted Answer

A)  NO 
B)  CO 
C)  HCO3- 
D)  O2 
E)  H2S 
A)  NO 
B)  CO 
C)  HCO3- 
D)  O2 
E)  H2S

Question 2

In general, ion channel-linked receptors are important to binding hormones such as insulin and steroids. Many common ion channel-linked receptors are cys-loop receptors, which have five subunit, and a total of about 20 helices important to spanning the lipid bilayer and interacting with ligands.

Accepted Answer

A)  Both sentences are true 
B)  Both sentences are false 
C)  The first sentence is true and the second sentence is false 
D)  The first sentence is false and the second sentence is true 
A)  Both sentences are true 
B)  Both sentences are false 
C)  The first sentence is true and the second sentence is false 
D)  The first sentence is false and the second sentence is true

Question 3

The graph to the right, where YO2 represents %O2 saturation, will be used for the following questions  
-Plot ___ is ___ and represents ___

Accepted Answer

A)  A; hyperbolic; myoglobin 
B)  B; sigmoidal; hemoglobin 
C)  B; hyperbolic; hemoglobin 
D)  A; sigmoidal; hemoglobin 
E)  Both A and B 
A)  A; hyperbolic; myoglobin 
B)  B; sigmoidal; hemoglobin 
C)  B; hyperbolic; hemoglobin 
D)  A; sigmoidal; hemoglobin 
E)  Both A and B

Question 4

The idea that binding of one molecule of oxygen to hemoglobin enhances further binding of oxygen to hemoglobin is called _____.

Accepted Answer

A)  homologous binding 
B)  cooperativity 
C)  fractional saturation 
D)  allosterism 
E)  none of the above 
A)  homologous binding 
B)  cooperativity 
C)  fractional saturation 
D)  allosterism 
E)  none of the above

Question 5

At active muscle
I. pCO2 is high
II. acidity is low
III. carbamate forms
IV. hemoglobin is stabilized in the T state

Accepted Answer

A)  I only 
B)  I and III 
C)  II, III and IV 
D)  I, III and IV 
E)  I, II, III and IV 
A)  I only 
B)  I and III 
C)  II, III and IV 
D)  I, III and IV 
E)  I, II, III and IV

Question 6

In hemoglobin of sickle cell anemia patients, a ___ residue is replaced by a ___ residue.

Accepted Answer

The answer of In hemoglobin of sickle cell anemia patients,...

Question 7

Ligands bind membrane bound receptors via

Accepted Answer

A)  hydrogen bonds 
B)  hydrophobic interactions 
C)  disulfide bonds 
D)  Both A and B 
E)  All of the above 
A)  hydrogen bonds 
B)  hydrophobic interactions 
C)  disulfide bonds 
D)  Both A and B 
E)  All of the above

Question 8

Myoglobin is _____; hemoglobin is _____.

Accepted Answer

A)  monomeric; dimeric 
B)  monomeric; trimeric 
C)  monomeric; tetrameric 
D)  dimeric; trimeric 
E)  dimeric; tetrameric 
A)  monomeric; dimeric 
B)  monomeric; trimeric 
C)  monomeric; tetrameric 
D)  dimeric; trimeric 
E)  dimeric; tetrameric

Question 9

Which of the following best explains the ability for carbon monoxide (CO) to bind to hemoglobin (HB. despite the relatively low concentrations of CO?

Accepted Answer

A)  CO binds to Hb with less affinity than oxygen 
B)  CO binds to Hb with an affinity about the same as oxygen 
C)  CO binds to Hb about 5 times more strongly than oxygen 
D)  CO binds to Hb about 250 times more strongly than oxygen 
E)  none of the above 
A)  CO binds to Hb with less affinity than oxygen 
B)  CO binds to Hb with an affinity about the same as oxygen 
C)  CO binds to Hb about 5 times more strongly than oxygen 
D)  CO binds to Hb about 250 times more strongly than oxygen 
E)  none of the above

Question 10

The individual hemoglobin subunits and myoglobin share similar _____ structure but have rather different _____ structure.

Accepted Answer

A)  primary; secondary 
B)  secondary; tertiary 
C)  primary; tertiary 
D)  secondary and tertiary; primary 
E)  primary and secondary; tertiary 
A)  primary; secondary 
B)  secondary; tertiary 
C)  primary; tertiary 
D)  secondary and tertiary; primary 
E)  primary and secondary; tertiary

Question 11

The structure of membrane bound receptors includes

Accepted Answer

A)  an intracellular ligand-binding domain 
B)  an extracellular domain that serves to induce intracellular changes 
C)  a catalytically-active site 
D)  None of the above 
A)  an intracellular ligand-binding domain 
B)  an extracellular domain that serves to induce intracellular changes 
C)  a catalytically-active site 
D)  None of the above

Question 12

With respect to oxygen saturation, hemoglobin is _____ saturated at the pO2 of the lungs and _____ saturated at the pO2 of the tissue

Accepted Answer

A)  20%; 20% 
B)  25%; 20% 
C)  50%; 20% 
D)  50%; between 30 and 70% 
E)  >90%; 10-30% 
A)  20%; 20% 
B)  25%; 20% 
C)  50%; 20% 
D)  50%; between 30 and 70% 
E)  >90%; 10-30%

Question 13

Many ion channel-linked receptors which respond to neurotransmitters such as acetylcholine and GABA allow passage of

Accepted Answer

A)  Na+ to afford an action potential or muscle contraction 
B)  Ca+2 to afford muscle contraction 
C)  Na+ to stimulate metabolic processes 
D)  Zn+ to stimulate inflammatory response 
E)  Fe+2 to encourage oxygen binding 
A)  Na+ to afford an action potential or muscle contraction 
B)  Ca+2 to afford muscle contraction 
C)  Na+ to stimulate metabolic processes 
D)  Zn+ to stimulate inflammatory response 
E)  Fe+2 to encourage oxygen binding

Question 14

A plot of ligand concentration vs receptor sites bound (a Scatchard plot)

Accepted Answer

A)  would likely be hyperbolic in nature for enzyme-linked receptors, because these have only one binding site and no subunits 
B)  would likely be sigmoidal in nature for enzyme-linked receptors, because these have only one binding site and no subunits 
C)  would likely be hyperbolic in nature for ion channel-linked receptors because they have several subunits that can be affected by sequential binding 
D)  would likely be hyperbolic in nature for G protein-linked receptors because they have several subunits that can be affected by sequential binding 
E)  would likely be hyperbolic in nature for G protein-linked receptors because they have several subunits that can be affected by concerted binding 
A)  would likely be hyperbolic in nature for enzyme-linked receptors, because these have only one binding site and no subunits 
B)  would likely be sigmoidal in nature for enzyme-linked receptors, because these have only one binding site and no subunits 
C)  would likely be hyperbolic in nature for ion channel-linked receptors because they have several subunits that can be affected by sequential binding 
D)  would likely be hyperbolic in nature for G protein-linked receptors because they have several subunits that can be affected by sequential binding 
E)  would likely be hyperbolic in nature for G protein-linked receptors because they have several subunits that can be affected by concerted binding

Question 15

Allosterism

Accepted Answer

A)  means "other shape" 
B)  is induced by binding of another molecule to a protein 
C)  is important to protein regulation 
D)  leads to change in conformation and activity 
E)  All of the above 
A)  means "other shape" 
B)  is induced by binding of another molecule to a protein 
C)  is important to protein regulation 
D)  leads to change in conformation and activity 
E)  All of the above

Question 16

At high pCO2, the oxygen binding curve of hemoglobin, demonstrating the Bohr effect

Accepted Answer

A)  takes on a hyperbolic shape 
B)  shifts to the right 
C)  shifts to the left 
D)  Both A and B are correct 
E)  None of the above 
A)  takes on a hyperbolic shape 
B)  shifts to the right 
C)  shifts to the left 
D)  Both A and B are correct 
E)  None of the above

Question 17

A plot of the binding of oxygen to myoglobin as a function of pO2 gives a _____ shape; a similar plot for hemoglobin gives a _____ shape.

Accepted Answer

A)  sigmoidal; sigmoidal 
B)  sigmoidal; hyperbolic 
C)  hyperbolic; sigmoidal 
D)  hyperbolic; hyperbolic 
E)  hyperbolic; exponential 
A)  sigmoidal; sigmoidal 
B)  sigmoidal; hyperbolic 
C)  hyperbolic; sigmoidal 
D)  hyperbolic; hyperbolic 
E)  hyperbolic; exponential

Question 18

In the ______ state of hemoglobin, the iron ion is out of the plane of the porphyrin ring.

Accepted Answer

The answer of In the ______ state of hemoglobin, the...

Question 19

What is the difference between allosteric and orthosteric regulation?

Accepted Answer

A)  All enzymes are regulated orthosterically only. 
B)  All enzymes are regulated allosterically only. 
C)  Only in allosteric regulation of an enzyme does the substrate bind to the active site 
D)  In allosteric regulation of an enzyme, the substrate binds to the allosteric site 
E)  In allosteric regulation of an enzyme, a molecule other than the substrate binds a site other than the active site 
A)  All enzymes are regulated orthosterically only. 
B)  All enzymes are regulated allosterically only. 
C)  Only in allosteric regulation of an enzyme does the substrate bind to the active site 
D)  In allosteric regulation of an enzyme, the substrate binds to the allosteric site 
E)  In allosteric regulation of an enzyme, a molecule other than the substrate binds a site other than the active site

Question 20

The graph to the right, where YO2 represents %O2 saturation, will be used for the following questions  
-Point C on the graph above

Accepted Answer

A)  represents the situation in the lung, where oxygen is abundant 
B)  oxygen is bound tightly to hemoglobin 
C)  represents the situation in the tissues, where oxygen is abundant 
D)  represents the situation in the tissues, where oxygen is deficient 
E)  hemoglobin is saturated with oxygen 
A)  represents the situation in the lung, where oxygen is abundant 
B)  oxygen is bound tightly to hemoglobin 
C)  represents the situation in the tissues, where oxygen is abundant 
D)  represents the situation in the tissues, where oxygen is deficient 
E)  hemoglobin is saturated with oxygen

Exam 19: Allosterism and Receptor-Ligand

Which gas does NOT bind to the heme Fe+2 ion in myoglobin?

In general, ion channel-linked receptors are important to binding hormones such as insulin and steroids. Many common ion channel-linked receptors are cys-loop receptors, which have five subunit, and a total of about 20 helices important to spanning the lipid bilayer and interacting with ligands.

The graph to the right, where YO2 represents %O2 saturation, will be used for the following questions -Plot ___ is ___ and represents ___

The idea that binding of one molecule of oxygen to hemoglobin enhances further binding of oxygen to hemoglobin is called _____.

At active muscle I. pCO2 is high II. acidity is low III. carbamate forms IV. hemoglobin is stabilized in the T state

In hemoglobin of sickle cell anemia patients, a ___ residue is replaced by a ___ residue.

Ligands bind membrane bound receptors via

Myoglobin is _____; hemoglobin is _____.

Which of the following best explains the ability for carbon monoxide (CO) to bind to hemoglobin (HB. despite the relatively low concentrations of CO?

The individual hemoglobin subunits and myoglobin share similar _____ structure but have rather different _____ structure.

The structure of membrane bound receptors includes

With respect to oxygen saturation, hemoglobin is _____ saturated at the pO2 of the lungs and _____ saturated at the pO2 of the tissue

Many ion channel-linked receptors which respond to neurotransmitters such as acetylcholine and GABA allow passage of

A plot of ligand concentration vs receptor sites bound (a Scatchard plot)

Allosterism

At high pCO2, the oxygen binding curve of hemoglobin, demonstrating the Bohr effect

A plot of the binding of oxygen to myoglobin as a function of pO2 gives a _____ shape; a similar plot for hemoglobin gives a _____ shape.

In the ______ state of hemoglobin, the iron ion is out of the plane of the porphyrin ring.

What is the difference between allosteric and orthosteric regulation?

The graph to the right, where YO2 represents %O2 saturation, will be used for the following questions -Point C on the graph above

The Chemical Foundations of Biochemistry

Nucleic Acids

Proteins I

Proteins Iienzymes

Membranes and an Introduction to Signal Transduction

Carbohydrates I

The Common Catabolic Pathway

Carbohydrates II

Lipids I

Lipids II

Amine Metabolism

Metabolism Integration

Nucleotide Deoxynucleotide Metabolism

Dna Replication, Damage and Repair

Rna Synthesis

Protein

Control of Gene

Determination of Macromolecular Structure

Designer Proteins and Protein Folding

Biomolecule Purification

Bioinformatics and Omics

Signal

Protein Trafficking

Photosynthesis Nitrogen

Filters

The graph to the right, where YO2 represents %O2 saturation, will be used for the following questions -Plot _ is _ and represents ___

In hemoglobin of sickle cell anemia patients, a _ residue is replaced by a _ residue.

Myoglobin is _; hemoglobin is _.

The individual hemoglobin subunits and myoglobin share similar _ structure but have rather different _ structure.

With respect to oxygen saturation, hemoglobin is _ saturated at the pO₂ of the lungs and _ saturated at the pO₂ of the tissue

A plot of the binding of oxygen to myoglobin as a function of pO2 gives a _ shape; a similar plot for hemoglobin gives a _ shape.