Question 1

Matching
-When oxygen binds to heme, the oxygen forms a hydrogen bond with ______.

Accepted Answer

A) positively cooperative 
B) cyanosis 
C) His E7 
D) decrease 
E) R
F)hydrogen bonds
G)increase
H)symmetry
I)His F8
J)ion pairs
K)T
L)hemolytic anemia
M)sequencial 
A) positively cooperative 
B) cyanosis 
C) His E7 
D) decrease 
E) R
F)hydrogen bonds
G)increase
H)symmetry
I)His F8
J)ion pairs
K)T
L)hemolytic anemia
M)sequencial

Question 2

Fab fragments can be generated by

Accepted Answer

A) reduction of IgG molecules. 
B) oxidation of IgG molecules. 
C) limited digestion of IgG molecules with papain. 
D) combining two light chains. 
E) combining two heavy chains. 
A) reduction of IgG molecules. 
B) oxidation of IgG molecules. 
C) limited digestion of IgG molecules with papain. 
D) combining two light chains. 
E) combining two heavy chains.

Question 3

Matching
-The absence of 2,3-BPG causes hemoglobin's affinity for oxygen to______.

Accepted Answer

A) positively cooperative 
B) cyanosis 
C) His E7 
D) decrease 
E) R
F)hydrogen bonds
G)increase
H)symmetry
I)His F8
J)ion pairs
K)T
L)hemolytic anemia
M)sequencial 
A) positively cooperative 
B) cyanosis 
C) His E7 
D) decrease 
E) R
F)hydrogen bonds
G)increase
H)symmetry
I)His F8
J)ion pairs
K)T
L)hemolytic anemia
M)sequencial

Question 4

The energy needed to drive muscle contraction comes from ATP hydrolysis that is carried out by

Accepted Answer

A) G-actin. 
B) F-actin. 
C) myosin heads. 
D) myosin tails. 
E) tropomyosin. 
A) G-actin. 
B) F-actin. 
C) myosin heads. 
D) myosin tails. 
E) tropomyosin.

Question 5

Some abnormal hemoglobins have Hill coefficients that are ______ that of normal hemoglobin, indicating that their ability to bind oxygen cooperatively has been compromised.

Accepted Answer

A) less than 
B) greater than 
C) much greater than 
D) about equal to 
E) The correct answer cannot be determined from the information given. 
A) less than 
B) greater than 
C) much greater than 
D) about equal to 
E) The correct answer cannot be determined from the information given.

Question 6

Which statement about antigen-binding sites in antibodies is false?

Accepted Answer

A) An antigen-binding site on an IgG is formed by the amino-terminal ~110 amino acids of a light chain and the amino terminal ~110 amino acids of a heavy chain. 
B) An antigen-binding site on an IgG is formed by the variable region of a light chain and the variable region of a heavy chain. 
C) The antigen-binding site is composed of two Ig folds. 
D) Antigen-binding specificity is determined by the sequences of the hypervariable sequences in both the light chain and the heavy chain. 
E) Antigen binding specificity is determined exclusively by the sequences in the carboxy-terminal ~110 amino acids in the light chain and the heavy chain. 
A) An antigen-binding site on an IgG is formed by the amino-terminal ~110 amino acids of a light chain and the amino terminal ~110 amino acids of a heavy chain. 
B) An antigen-binding site on an IgG is formed by the variable region of a light chain and the variable region of a heavy chain. 
C) The antigen-binding site is composed of two Ig folds. 
D) Antigen-binding specificity is determined by the sequences of the hypervariable sequences in both the light chain and the heavy chain. 
E) Antigen binding specificity is determined exclusively by the sequences in the carboxy-terminal ~110 amino acids in the light chain and the heavy chain.

Question 7

Which of the statements about muscle contraction is not true?

Accepted Answer

A) During muscle contraction the sarcomere becomes shorter. 
B) During muscle contraction the I band becomes shorter. 
C) During muscle contraction the H zone becomes shorter. 
D) During muscle contraction the A band becomes shorter 
E) During muscle contraction the distance between the Z disk and the M disk becomes shorter. 
A) During muscle contraction the sarcomere becomes shorter. 
B) During muscle contraction the I band becomes shorter. 
C) During muscle contraction the H zone becomes shorter. 
D) During muscle contraction the A band becomes shorter 
E) During muscle contraction the distance between the Z disk and the M disk becomes shorter.

Question 8

Matching
-The ______ model of allosterism requires subunits to change conformation simultaneously.

Accepted Answer

A) positively cooperative 
B) cyanosis 
C) His E7 
D) decrease 
E) R
F)hydrogen bonds
G)increase
H)symmetry
I)His F8
J)ion pairs
K)T
L)hemolytic anemia
M)sequencial 
A) positively cooperative 
B) cyanosis 
C) His E7 
D) decrease 
E) R
F)hydrogen bonds
G)increase
H)symmetry
I)His F8
J)ion pairs
K)T
L)hemolytic anemia
M)sequencial

Question 9

Which of the statements about muscle contraction is correct?

Accepted Answer

A) During muscle contraction the sarcomere becomes shorter. 
B) During muscle contraction the I band becomes shorter. 
C) During muscle contraction the H zone becomes shorter. 
D) During muscle contraction the distance between the Z disk and the M disk becomes shorter. 
E) All of the answers above are correct. 
A) During muscle contraction the sarcomere becomes shorter. 
B) During muscle contraction the I band becomes shorter. 
C) During muscle contraction the H zone becomes shorter. 
D) During muscle contraction the distance between the Z disk and the M disk becomes shorter. 
E) All of the answers above are correct.

Question 10

Which of the following increases the affinity of hemoglobin for O2?

Accepted Answer

A) an increase in BPG concentration 
B) the formation of N-terminal carbamates 
C) an increase in pH 
D) a decrease in pH 
E) an increase in CO2 concentration 
A) an increase in BPG concentration 
B) the formation of N-terminal carbamates 
C) an increase in pH 
D) a decrease in pH 
E) an increase in CO2 concentration

Question 11

The graph below shows the O2-binding curves for myoglobin (Mb)and hemoglobin (Hb).
a.Label the two curves (indicate which one represents Mb and which one represents Hb).   b.Use the graph to determine the Kd of myoglobin for O2 (show your approach).
c.What is the difference between myoglobin and hemoglobin that cause the O2-binding curves to so be different?
d.Why is it important that hemoglobin has these particular O2-binding characteristics?

Accepted Answer

a.See graph. @#IMG-DLM& b.K_d equals 3-4 torr (see g

Question 12

What are the main bonds or forces that stabilize the dimer formed by two myosin heavy chains?

Accepted Answer

A) hydrophobic interactions 
B) hydrogen-bonds 
C) ionic interactions 
D) disulfide bonds 
E) isopeptide bonds 
A) hydrophobic interactions 
B) hydrogen-bonds 
C) ionic interactions 
D) disulfide bonds 
E) isopeptide bonds

Question 13

The primary structure of mammalian hemoglobin, an $\alpha$2$\beta$2 tetramer, is approximately _____ identical to myoglobin.

Accepted Answer

A) 2% 
B) 18% 
C) 50% 
D) 78% 
E) 98% 
A) 2% 
B) 18% 
C) 50% 
D) 78% 
E) 98%

Question 14

During the T to R conformational shift, Fe(II)drags the F-helix via a bond to the side chain of ________.

Accepted Answer

A) Leu F7 
B) Leu F4 
C) His F8 
D) Leu FG3 
E) Val FG5 
A) Leu F7 
B) Leu F4 
C) His F8 
D) Leu FG3 
E) Val FG5

Question 15

Which class of antibodies has been implicated in allergic reactions?

Accepted Answer

A) IgA 
B) IgD 
C) IgE 
D) IgG 
E) IgM 
A) IgA 
B) IgD 
C) IgE 
D) IgG 
E) IgM

Question 16

Muscle contraction is directly caused by

Accepted Answer

A) structural changes in actin. 
B) structural changes in myosin. 
C) thick and thin filaments sliding past each other. 
D) structural changes in the Z disk. 
E) None of the above is correct. 
A) structural changes in actin. 
B) structural changes in myosin. 
C) thick and thin filaments sliding past each other. 
D) structural changes in the Z disk. 
E) None of the above is correct.

Question 17

Hemoglobin's p50 value is about ______ as great as myoglobin's p50 value.

Accepted Answer

A) one-tenth 
B) half 
C) twice 
D) ten times 
E) twenty times 
A) one-tenth 
B) half 
C) twice 
D) ten times 
E) twenty times

Question 18

Which of the following statements does not apply to the K value in the equation for the oxygen binding curve of myoglobin?

Accepted Answer

A) It is numerically equal to p50. 
B) It is defined as that oxygen partial pressure at which half of the oxygen binding sites are occupied. 
C) It is a measure of the affinity of myoglobin for oxygen. 
D) If Y > K, then myoglobin is less than 50% saturated with oxygen. 
E) It is the value of pO2 at which Y = 0.5. 
A) It is numerically equal to p50. 
B) It is defined as that oxygen partial pressure at which half of the oxygen binding sites are occupied. 
C) It is a measure of the affinity of myoglobin for oxygen. 
D) If Y > K, then myoglobin is less than 50% saturated with oxygen. 
E) It is the value of pO2 at which Y = 0.5.

Question 19

Carbon monoxide binds to heme:

Accepted Answer

A) with a higher affinity than oxygen. 
B) resulting in the oxidation of the Fe(II)to Fe(III) 
C) in a manner that displaces carbon dioxide, causing CO2 poisoning. 
D) from the side opposite oxygen, resulting in a brown colored heme. 
E) with a lower affinity than oxygen. 
A) with a higher affinity than oxygen. 
B) resulting in the oxidation of the Fe(II)to Fe(III) 
C) in a manner that displaces carbon dioxide, causing CO2 poisoning. 
D) from the side opposite oxygen, resulting in a brown colored heme. 
E) with a lower affinity than oxygen.

Question 20

The rearrangement of T state hemoglobin to the R state

Accepted Answer

A) occurs in each protein subunit independently when its heme binds oxygen. 
B) requires the binding of at least three oxygen molecules. 
C) increases the ion pairing interactions of the C-terminal amino acids. 
D) involves the movement of the Fe(II)into the heme plane. 
E) opens a central cavity for BPG binding. 
A) occurs in each protein subunit independently when its heme binds oxygen. 
B) requires the binding of at least three oxygen molecules. 
C) increases the ion pairing interactions of the C-terminal amino acids. 
D) involves the movement of the Fe(II)into the heme plane. 
E) opens a central cavity for BPG binding.

Exam 7: Protein Function Part I: Myoglobin and Hemoglobin

Matching -When oxygen binds to heme, the oxygen forms a hydrogen bond with ______.

Fab fragments can be generated by

Matching -The absence of 2,3-BPG causes hemoglobin's affinity for oxygen to______.

The energy needed to drive muscle contraction comes from ATP hydrolysis that is carried out by

Some abnormal hemoglobins have Hill coefficients that are ______ that of normal hemoglobin, indicating that their ability to bind oxygen cooperatively has been compromised.

Which statement about antigen-binding sites in antibodies is false?

Which of the statements about muscle contraction is not true?

Matching -The ______ model of allosterism requires subunits to change conformation simultaneously.

Which of the statements about muscle contraction is correct?

Which of the following increases the affinity of hemoglobin for O2?

What are the main bonds or forces that stabilize the dimer formed by two myosin heavy chains?

The primary structure of mammalian hemoglobin, an α\alphaα 2 β\betaβ 2 tetramer, is approximately _____ identical to myoglobin.

During the T to R conformational shift, Fe(II)drags the F-helix via a bond to the side chain of ________.

Which class of antibodies has been implicated in allergic reactions?

Muscle contraction is directly caused by

Hemoglobin's p50 value is about ______ as great as myoglobin's p50 value.

Which of the following statements does not apply to the K value in the equation for the oxygen binding curve of myoglobin?

Carbon monoxide binds to heme:

The rearrangement of T state hemoglobin to the R state

Introduction to the Chemistry of Life

Water

Nucleotides, Nucleic Acids, and Genetic Information

Amino Acids

Proteins: Primary Structure

Proteins: Three-Dimensional Structure

Carbohydrates

Lipids and Biological Membranes

Membrane Transport

Enzyme Catalysis

Enzyme Kinetics, Inhibition and Control

Biochemical Signaling

Introduction to Metabolism

Glycogen Metabolism and Gluconeogenesis

Glucose Catabolism

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

Translation

Regulation of Gene Expression

Filters

Which of the following increases the affinity of hemoglobin for O₂?

The primary structure of mammalian hemoglobin, an $\alpha$ ₂ $\beta$ ₂ tetramer, is approximately _____ identical to myoglobin.

Hemoglobin's p₅₀ value is about ______ as great as myoglobin's p₅₀ value.