Summary Bio 1100 Exam 2 RevieW
QUESTIONS AND CORRECT ANSWERS
a.a coenzyme b.an allosteric inhibitor c.the substrate
d.an intermediate e.a competitive inhibitor - ANSWERSb.How might a change of one amino acid at a
site, distant from the active site of an enzyme, alter an enzyme's substrate specificity?
a.by changing the enzyme's stability
b.by changing the enzyme's location in the cell
c.by changing the shape of an enzyme
d.by changing the enzyme's pH optimum
e.An amino acid change away from the active site cannot alter the enzyme's substrate - ANSWERSc.Zinc,
an essential trace element for most organisms, is present in the active site of the enzyme
carboxypeptidase. The zinc most likely functions as _____.
best at a pH of 3 and a temperature of 90°C
b.Enzyme A-functions best at a pH of 10 and a temperature of 90°C
c.Enzyme D-functions best at a pH of 7 and a temperature of 50°C
d.Enzyme C-functions best at a pH of 10 and a temperature of 30°C - ANSWERSa.During a laboratory
experiment, you discover that an enzyme-catalyzed reaction has a ∆G of -20 kcal/mol. If you double the
amount of enzyme in the reaction, what will be the ∆G for the new reaction?
a. -40 kcal/mol b. -20 kcal/mol c. 0 kcal/mol d. +20 kcal/mol e. +40 kcal/mol - ANSWERSb.Catabolic
pathways _____.
a.combine molecules into more energy-rich molecules
b.supply energy, primarily in the form of ATP, for the cell's work
c.are endergonic
d.are spontaneous and do not need enzyme catalysis
e.build up complex molecules such as protein from simpler compounds - ANSWERSb.When considering
cell metabolism, carbohydrates __________________ energy, and via the process of energetic coupling,
ATP hydrolysis ___________________ energy to drive otherwise non spontaneous processes.
a.store; consumes b.store; releases
c.consume; stores d.release; consumes - ANSWERSb.Compare the molecular formula of a carbohydrate
(CH2O)n with that of carbon dioxide (CO2). What does the presence of hydrogen atoms in
,carbohydrates indicate? (Hint: think about the electronegativities of the involved atoms, their position in
the orbitals, and the phrase: "OIL RIG" or "LEO the lion goes GER"
a.Carbohydrates are more reduced than carbon dioxide.
b.Carbohydrates are more oxidized than carbon dioxide.
c.Every carbon atom in a carbohydrate is bonded to four different atoms.
d.Carbohydrates contain a carbonyl functional group. - ANSWERSa.What is the fate of the phosphate
group that is removed when ATP is converted to ADP?
a.It is broken down into one phosphorus and four oxygen atoms.
b.It is used to convert an ATP into an AQP.
c.It is acquired by a reactant in an exergonic reaction.
d.It is acquired by a reactant in a spontaneous reaction.
e.It is acquired by a reactant in an endergonic reaction. - ANSWERSe.Which of the following statements
is not true of most cellular redox reactions?
a.Changes in potential energy can be released as heat.
b.The reactant that is oxidized loses electrons.
c.A hydrogen atom is transferred to the atom that loses an electron.
d.The electron acceptor is reduced. - ANSWERSc.The lowering of activation energy during the transition
step of enzyme catalysis depends on _____ at the enzyme's active site.
a. products orienting precisely b. interactions with R-groups
c. temperatures rising d. products being released - ANSWERSb.A series of enzymes catalyze the reaction
X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active
site. This binding decreases the activity of the enzyme. What is substance X?
a.a coenzyme b.an allosteric inhibitor c.a substrate
d.an intermediate e.the product - ANSWERSc.A series of enzymes catalyze the reaction X → Y → Z → A.
Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding
decreases the activity of the enzyme. With respect to the enzyme that converts X to Y, substance A
functions as _____.
a.a coenzyme b.an allosteric inhibitor c.the substrate
d.an intermediate e.a competitive inhibitor - ANSWERSb.How might a change of one amino acid at a
site, distant from the active site of an enzyme, alter an enzyme's substrate specificity?
a.by changing the enzyme's stability
, b.by changing the enzyme's location in the cell
c.by changing the shape of an enzyme
d.by changing the enzyme's pH optimum
e.An amino acid change away from the active site cannot alter the enzyme's substrate - ANSWERSc.Zinc,
an essential trace element for most organisms, is present in the active site of the enzyme
carboxypeptidase. The zinc most likely functions as _____.
a.a competitive inhibitor of the enzyme
b.a noncompetitive inhibitor of the enzyme
c.an allosteric activator of the enzyme
d.a cofactor necessary for enzyme activity
e.a coenzyme derived from a vitamin - ANSWERSd.According to the induced fit hypothesis of enzyme
catalysis, _____.
a.the binding of the substrate depends on the shape of the active site
b.some enzymes change their structure when activators bind to the enzyme
c.a competitive inhibitor can outcompete the substrate for the active site
d.the binding of the substrate changes the shape of the enzyme's active site
e.the active site creates a microenvironment ideal for the reaction - ANSWERSd.Which of the following
statements is true about enzyme-catalyzed reactions?
a.The reaction is faster than the same reaction in the absence of the enzyme.
b.The free energy change of the reaction is opposite from the reaction that occurs in the absence of the
enzyme.
c.An enzyme catalyzes a reaction by raising the activation energy.
d.Enzyme-catalyzed reactions require energy to activate the enzyme.
e.Enzyme-catalyzed reactions release more free energy than noncatalyzed reactions - ANSWERSa.What
is the difference between a monosaccharide, an oligosaccharide, and a polysaccharide?
a.the number of monomers in the molecule
b.the spatial arrangement of the various hydroxyl residues in the molecule
c.the type of glycosidic linkage between monomers
d.the number of carbon atoms joined in a ring in the molecule - ANSWERSa.What are three ways alpha
monosaccharides differ from one another?
QUESTIONS AND CORRECT ANSWERS
a.a coenzyme b.an allosteric inhibitor c.the substrate
d.an intermediate e.a competitive inhibitor - ANSWERSb.How might a change of one amino acid at a
site, distant from the active site of an enzyme, alter an enzyme's substrate specificity?
a.by changing the enzyme's stability
b.by changing the enzyme's location in the cell
c.by changing the shape of an enzyme
d.by changing the enzyme's pH optimum
e.An amino acid change away from the active site cannot alter the enzyme's substrate - ANSWERSc.Zinc,
an essential trace element for most organisms, is present in the active site of the enzyme
carboxypeptidase. The zinc most likely functions as _____.
best at a pH of 3 and a temperature of 90°C
b.Enzyme A-functions best at a pH of 10 and a temperature of 90°C
c.Enzyme D-functions best at a pH of 7 and a temperature of 50°C
d.Enzyme C-functions best at a pH of 10 and a temperature of 30°C - ANSWERSa.During a laboratory
experiment, you discover that an enzyme-catalyzed reaction has a ∆G of -20 kcal/mol. If you double the
amount of enzyme in the reaction, what will be the ∆G for the new reaction?
a. -40 kcal/mol b. -20 kcal/mol c. 0 kcal/mol d. +20 kcal/mol e. +40 kcal/mol - ANSWERSb.Catabolic
pathways _____.
a.combine molecules into more energy-rich molecules
b.supply energy, primarily in the form of ATP, for the cell's work
c.are endergonic
d.are spontaneous and do not need enzyme catalysis
e.build up complex molecules such as protein from simpler compounds - ANSWERSb.When considering
cell metabolism, carbohydrates __________________ energy, and via the process of energetic coupling,
ATP hydrolysis ___________________ energy to drive otherwise non spontaneous processes.
a.store; consumes b.store; releases
c.consume; stores d.release; consumes - ANSWERSb.Compare the molecular formula of a carbohydrate
(CH2O)n with that of carbon dioxide (CO2). What does the presence of hydrogen atoms in
,carbohydrates indicate? (Hint: think about the electronegativities of the involved atoms, their position in
the orbitals, and the phrase: "OIL RIG" or "LEO the lion goes GER"
a.Carbohydrates are more reduced than carbon dioxide.
b.Carbohydrates are more oxidized than carbon dioxide.
c.Every carbon atom in a carbohydrate is bonded to four different atoms.
d.Carbohydrates contain a carbonyl functional group. - ANSWERSa.What is the fate of the phosphate
group that is removed when ATP is converted to ADP?
a.It is broken down into one phosphorus and four oxygen atoms.
b.It is used to convert an ATP into an AQP.
c.It is acquired by a reactant in an exergonic reaction.
d.It is acquired by a reactant in a spontaneous reaction.
e.It is acquired by a reactant in an endergonic reaction. - ANSWERSe.Which of the following statements
is not true of most cellular redox reactions?
a.Changes in potential energy can be released as heat.
b.The reactant that is oxidized loses electrons.
c.A hydrogen atom is transferred to the atom that loses an electron.
d.The electron acceptor is reduced. - ANSWERSc.The lowering of activation energy during the transition
step of enzyme catalysis depends on _____ at the enzyme's active site.
a. products orienting precisely b. interactions with R-groups
c. temperatures rising d. products being released - ANSWERSb.A series of enzymes catalyze the reaction
X → Y → Z → A. Product A binds to the enzyme that converts X to Y at a position remote from its active
site. This binding decreases the activity of the enzyme. What is substance X?
a.a coenzyme b.an allosteric inhibitor c.a substrate
d.an intermediate e.the product - ANSWERSc.A series of enzymes catalyze the reaction X → Y → Z → A.
Product A binds to the enzyme that converts X to Y at a position remote from its active site. This binding
decreases the activity of the enzyme. With respect to the enzyme that converts X to Y, substance A
functions as _____.
a.a coenzyme b.an allosteric inhibitor c.the substrate
d.an intermediate e.a competitive inhibitor - ANSWERSb.How might a change of one amino acid at a
site, distant from the active site of an enzyme, alter an enzyme's substrate specificity?
a.by changing the enzyme's stability
, b.by changing the enzyme's location in the cell
c.by changing the shape of an enzyme
d.by changing the enzyme's pH optimum
e.An amino acid change away from the active site cannot alter the enzyme's substrate - ANSWERSc.Zinc,
an essential trace element for most organisms, is present in the active site of the enzyme
carboxypeptidase. The zinc most likely functions as _____.
a.a competitive inhibitor of the enzyme
b.a noncompetitive inhibitor of the enzyme
c.an allosteric activator of the enzyme
d.a cofactor necessary for enzyme activity
e.a coenzyme derived from a vitamin - ANSWERSd.According to the induced fit hypothesis of enzyme
catalysis, _____.
a.the binding of the substrate depends on the shape of the active site
b.some enzymes change their structure when activators bind to the enzyme
c.a competitive inhibitor can outcompete the substrate for the active site
d.the binding of the substrate changes the shape of the enzyme's active site
e.the active site creates a microenvironment ideal for the reaction - ANSWERSd.Which of the following
statements is true about enzyme-catalyzed reactions?
a.The reaction is faster than the same reaction in the absence of the enzyme.
b.The free energy change of the reaction is opposite from the reaction that occurs in the absence of the
enzyme.
c.An enzyme catalyzes a reaction by raising the activation energy.
d.Enzyme-catalyzed reactions require energy to activate the enzyme.
e.Enzyme-catalyzed reactions release more free energy than noncatalyzed reactions - ANSWERSa.What
is the difference between a monosaccharide, an oligosaccharide, and a polysaccharide?
a.the number of monomers in the molecule
b.the spatial arrangement of the various hydroxyl residues in the molecule
c.the type of glycosidic linkage between monomers
d.the number of carbon atoms joined in a ring in the molecule - ANSWERSa.What are three ways alpha
monosaccharides differ from one another?
