Question 1

Which of the following explains the conversion of hemoglobin subunits from deoxy to oxy state?

Accepted Answer

A)  all four subunits switch simultaneously 
B)  each subunit switches only upon oxygen binding to the particular subunit 
C)  both  $\alpha$  subunits simultaneously switch first followed by both  $\beta$  subunits 
D)  both  $\beta$  subunits simultaneously switch first followed by both $\alpha$
  subunits 
E)  none of the above 
A)  all four subunits switch simultaneously 
B)  each subunit switches only upon oxygen binding to the particular subunit 
C)  both  $\alpha$  subunits simultaneously switch first followed by both  $\beta$  subunits 
D)  both  $\beta$  subunits simultaneously switch first followed by both $\alpha$
  subunits 
E)  none of the above A

Question 2

In a muscle cell, what is the name for the bundles of myosin tails?

Accepted Answer

A)  cytoskeleton 
B)  thick filaments 
C)  intermediate filaments 
D)  thin filaments 
E)  none of the above 
A)  cytoskeleton 
B)  thick filaments 
C)  intermediate filaments 
D)  thin filaments 
E)  none of the above B

Question 3

Which of the following explains how cell division is blocked by drugs that prevent proper microtubule function?

Accepted Answer

A)  the condensation of chromatin requires a microtubule skeleton 
B)  production of new membranes for organelles and nucleus requires microtubules 
C)  chromosomes separate along a microtubule spindle 
D)  division of organelles between daughter cells requires organelle movement along microtubules 
E)  none of the above 
A)  the condensation of chromatin requires a microtubule skeleton 
B)  production of new membranes for organelles and nucleus requires microtubules 
C)  chromosomes separate along a microtubule spindle 
D)  division of organelles between daughter cells requires organelle movement along microtubules 
E)  none of the above C

Question 4

Which of the following correctly describes the sequence of events in the kinesin reaction cycle? For simplicity, the two heads are referred to as head 1 and head 2. Head 1 starts as the leading head.

Accepted Answer

A)  head 1 releases tubulin, ATP binds to head 1, head 2 swings forward, head 2 binds to tubulin, ADP release from head 2, ATP hydrolysis in head 1 
B)  ATP binds to head 1, head 2 swings forward, ADP release from head 2, ATP hydrolysis in head 1, head 2 binds to tubulin, head 1 releases tubulin 
C)  ATP binds to head 1, head 2 swings forward, head 2 binds to tubulin, ATP hydrolysis in head 1, ADP release from head 2, head 1 releases tubulin 
D)  ATP binds to head 1, head 2 swings forward, head 2 binds to tubulin, ADP release from head 2, ATP hydrolysis in head 1, head 1 releases tubulin 
E)  none of the above 
A)  head 1 releases tubulin, ATP binds to head 1, head 2 swings forward, head 2 binds to tubulin, ADP release from head 2, ATP hydrolysis in head 1 
B)  ATP binds to head 1, head 2 swings forward, ADP release from head 2, ATP hydrolysis in head 1, head 2 binds to tubulin, head 1 releases tubulin 
C)  ATP binds to head 1, head 2 swings forward, head 2 binds to tubulin, ATP hydrolysis in head 1, ADP release from head 2, head 1 releases tubulin 
D)  ATP binds to head 1, head 2 swings forward, head 2 binds to tubulin, ADP release from head 2, ATP hydrolysis in head 1, head 1 releases tubulin 
E)  none of the above

Question 5

Bone and tendons contain _____ while hair and nails contain _____.

Accepted Answer

A)  collagen; keratin 
B)  actin; keratin 
C)  tubulin; collagen 
D)  collagen; actin 
E)  tubulin; keratin 
A)  collagen; keratin 
B)  actin; keratin 
C)  tubulin; collagen 
D)  collagen; actin 
E)  tubulin; keratin

Question 6

During the formation of microfilaments, which of the following occurs?

Accepted Answer

A)  ATP binds to F-actin 
B)  F-actin polymerizes, becoming G-actin 
C)  ATP hydrolysis is catalyzed by F-actin 
D)  polymerization proceeds quickly at first, then slows after about ten actin monomers have polymerized 
E)  none of the above 
A)  ATP binds to F-actin 
B)  F-actin polymerizes, becoming G-actin 
C)  ATP hydrolysis is catalyzed by F-actin 
D)  polymerization proceeds quickly at first, then slows after about ten actin monomers have polymerized 
E)  none of the above

Question 7

When a cell moves along a surface, actin _____ occurs at the leading edge while _____ occurs at the trailing edge

Accepted Answer

A)  polymerization; depolymerization 
B)  depolymerization; polymerization 
C)  denaturation; renaturation 
D)  renaturation; denaturation 
E)  none of the above 
A)  polymerization; depolymerization 
B)  depolymerization; polymerization 
C)  denaturation; renaturation 
D)  renaturation; denaturation 
E)  none of the above

Question 8

Which of the following represents the longest distance traveled by a kinesin-vesicle complex?

Accepted Answer

A)  movement of a mitochondria in a cardiac cell 
B)  movement of a neurotransmitter vesicle down the axon of a nerve cell 
C)  movement of a glucose filled vesicle to the membrane of a liver cell 
D)  movement of a lipid-filled vesicle within an intestinal cell 
E)  none of the above 
A)  movement of a mitochondria in a cardiac cell 
B)  movement of a neurotransmitter vesicle down the axon of a nerve cell 
C)  movement of a glucose filled vesicle to the membrane of a liver cell 
D)  movement of a lipid-filled vesicle within an intestinal cell 
E)  none of the above

Question 9

Which of the following correctly describes the sequence of events in the myosin-actin cycle?

Accepted Answer

A)  myosin release from actin, ATP binds to myosin, myosin binds to another actin subunit, release of Pi and ADP, stretched myosin returns to original conformation 
B)  myosin release from actin, ATP binds to myosin, myosin binds to another actin subunit, stretched myosin returns to original conformation, release of Pi and ADP 
C)  ATP binds to myosin, myosin release from actin, myosin binds to another actin subunit, release of Pi and ADP, stretched myosin returns to original conformation 
D)  ATP binds to myosin, myosin release from actin, myosin binds to another actin subunit, stretched myosin returns to original conformation, release of Pi and ADP 
E)  myosin release from actin, myosin binds to another actin subunit, ATP binds to myosin, stretched myosin returns to original conformation, release of Pi and ADP 
A)  myosin release from actin, ATP binds to myosin, myosin binds to another actin subunit, release of Pi and ADP, stretched myosin returns to original conformation 
B)  myosin release from actin, ATP binds to myosin, myosin binds to another actin subunit, stretched myosin returns to original conformation, release of Pi and ADP 
C)  ATP binds to myosin, myosin release from actin, myosin binds to another actin subunit, release of Pi and ADP, stretched myosin returns to original conformation 
D)  ATP binds to myosin, myosin release from actin, myosin binds to another actin subunit, stretched myosin returns to original conformation, release of Pi and ADP 
E)  myosin release from actin, myosin binds to another actin subunit, ATP binds to myosin, stretched myosin returns to original conformation, release of Pi and ADP

Question 10

Ascorbic acid is required for the production of _____ in collagen.

Accepted Answer

A)  hydroxylysine 
B)   $\gamma$ -carboxyglutamic acid 
C)  desmosine 
D)  aspartate  $\beta$ -semialdehyde 
E)  hydroxyproline 
A)  hydroxylysine 
B)   $\gamma$ -carboxyglutamic acid 
C)  desmosine 
D)  aspartate  $\beta$ -semialdehyde 
E)  hydroxyproline

Question 11

The heads of kinesin bind to _____; the light chains of kinesin bind to _____.

Accepted Answer

A)  tubulin; proteins in the membrane of a vesicle 
B)  proteins in the membrane of an organelle; tubulin 
C)  proteins in the membrane of a vesicle; actin 
D)  collagen fibers; proteins in the cell membrane 
E)  none of the above 
A)  tubulin; proteins in the membrane of a vesicle 
B)  proteins in the membrane of an organelle; tubulin 
C)  proteins in the membrane of a vesicle; actin 
D)  collagen fibers; proteins in the cell membrane 
E)  none of the above

Question 12

In Hb S, a ___ residue is replaced by a ___ residue.

Accepted Answer

The answer of In Hb S, a ___ residue is...

Question 13

Which of the following occurs in hemoglobin upon oxygen binding?

Accepted Answer

A)  the heme Fe2+ is pulled out of the plane of the heme group 
B)  the His coordinated to the heme Fe2+ is pushed away from the heme group 
C)  the central cavity between the four subunits is decreased in size 
D)  hemoglobin changes from the R state to the T state 
E)  all of the above occur 
A)  the heme Fe2+ is pulled out of the plane of the heme group 
B)  the His coordinated to the heme Fe2+ is pushed away from the heme group 
C)  the central cavity between the four subunits is decreased in size 
D)  hemoglobin changes from the R state to the T state 
E)  all of the above occur

Question 14

Which amino acid is critical for crosslinking of collagen trimers?

Accepted Answer

A)  Ser 
B)  Lys 
C)  His 
D)  Cys 
E)  Gln 
A)  Ser 
B)  Lys 
C)  His 
D)  Cys 
E)  Gln

Question 15

What is the prominent type of secondary structure observed in myoglobin?

Accepted Answer

A)   $\beta$ -helices 
B)  $\alpha$ -bends 
C)  parallel  $\beta$ -sheets 
D)  antiparallel  $\beta$ -sheets 
E)   $\alpha$ -helices 
A)   $\beta$ -helices 
B)  $\alpha$ -bends 
C)  parallel  $\beta$ -sheets 
D)  antiparallel  $\beta$ -sheets 
E)   $\alpha$ -helices

Question 16

Each kinesin head contains a binding site for _____ and a binding site for _____.

Accepted Answer

A)  tubulin; GTP 
B)  another kinesin molecule; GTP 
C)  myosin; ATP 
D)  actin; ATP 
E)  tubulin; ATP 
A)  tubulin; GTP 
B)  another kinesin molecule; GTP 
C)  myosin; ATP 
D)  actin; ATP 
E)  tubulin; ATP

Question 17

The helical structure of collagen contains _____.

Accepted Answer

A)  three right-handed helices wound around each other in a right-handed triple helix 
B)  three right-handed helices wound around each other in a left-handed triple helix 
C)  three left-handed helices wound around each other in a left-handed triple helix 
D)  three left-handed helices wound around each other in a right-handed triple helix 
E)  none of the above 
A)  three right-handed helices wound around each other in a right-handed triple helix 
B)  three right-handed helices wound around each other in a left-handed triple helix 
C)  three left-handed helices wound around each other in a left-handed triple helix 
D)  three left-handed helices wound around each other in a right-handed triple helix 
E)  none of the above

Question 18

What is the most prevalent secondary structure observed in the proteins of intermediate filaments?

Accepted Answer

A)   $\alpha$ -helices 
B)   $\beta$ -helices 
C)   $\alpha$ -sheets 
D)   $\beta$ -sheets 
E)  both  $\alpha$ -helices and  $\beta$ -helices are observed 
A)   $\alpha$ -helices 
B)   $\beta$ -helices 
C)   $\alpha$ -sheets 
D)   $\beta$ -sheets 
E)  both  $\alpha$ -helices and  $\beta$ -helices are observed

Question 19

Each myosin head contains a binding site for _____ and a binding site for _____.

Accepted Answer

A)  tubulin; GTP 
B)  another myosin molecule; ATP 
C)  kinesin; GTP 
D)  actin; ATP 
E)  none of the above 
A)  tubulin; GTP 
B)  another myosin molecule; ATP 
C)  kinesin; GTP 
D)  actin; ATP 
E)  none of the above

Question 20

The best-known hemoglobin variant is _____.

Accepted Answer

sickle cel

Exam 5: Protein Function

Which of the following explains the conversion of hemoglobin subunits from deoxy to oxy state?

In a muscle cell, what is the name for the bundles of myosin tails?

Which of the following explains how cell division is blocked by drugs that prevent proper microtubule function?

Which of the following correctly describes the sequence of events in the kinesin reaction cycle? For simplicity, the two heads are referred to as head 1 and head 2. Head 1 starts as the leading head.

Bone and tendons contain _____ while hair and nails contain _____.

During the formation of microfilaments, which of the following occurs?

When a cell moves along a surface, actin _____ occurs at the leading edge while _____ occurs at the trailing edge

Which of the following represents the longest distance traveled by a kinesin-vesicle complex?

Which of the following correctly describes the sequence of events in the myosin-actin cycle?

Ascorbic acid is required for the production of _____ in collagen.

The heads of kinesin bind to _____; the light chains of kinesin bind to _____.

In Hb S, a ___ residue is replaced by a ___ residue.

Which of the following occurs in hemoglobin upon oxygen binding?

Which amino acid is critical for crosslinking of collagen trimers?

What is the prominent type of secondary structure observed in myoglobin?

Each kinesin head contains a binding site for _____ and a binding site for _____.

The helical structure of collagen contains _____.

What is the most prevalent secondary structure observed in the proteins of intermediate filaments?

Each myosin head contains a binding site for _____ and a binding site for _____.

The best-known hemoglobin variant is _____.

The Chemical Basis of Life

Aqueous Chemistry

Nucleic Acid Structure and Function

Protein Structure

How Enzymes Work

Enzyme Kinetics and Inhibition

Lipids and Membranes

Membrane Transport

Signaling

Carbohydrates

Metabolism and Bioenergetics

Glucose Metabolism

The Citric Acid Cycle

Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Nitrogen Metabolism

Regulation of Mammalian Fuel Metabolism

DNA Replication and Repair

Transcription and RNA

Protein Synthesis

Filters

Bone and tendons contain _ while hair and nails contain _.

When a cell moves along a surface, actin _ occurs at the leading edge while _ occurs at the trailing edge

The heads of kinesin bind to _; the light chains of kinesin bind to _.

In Hb S, a _ residue is replaced by a _ residue.

Each kinesin head contains a binding site for _ and a binding site for _.

Each myosin head contains a binding site for _ and a binding site for _.