LS7A Midterm 2 question with answers
In eukaryotes, pyruvate oxidation takes place in the:
a. cytoplasm.
b. outer mitochondrial membrane.
c. inner mitochondrial membrane.
d. intermembrane space of mitochondria.
e. mitochondrial matrix. - -e. mitochondrial matrix
-When a single pyruvate is converted to acetyl-CoA, the other products of
the reaction are:
a. Pi and FADH2.
b. CO2 and ATP.
c. ATP and NADH.
d. FADH2 and ATP.
e. NADH and CO2. - -e. NADH and CO2
-Pyruvate oxidation is an important stage in cellular respiration because it:
a. generates ATP by substrate-level phosphorylation.
b. transfers large numbers of electrons to electron carriers.
c. is the first step in oxidative phosphorylation.
d. links glycolysis with the citric acid cycle.
e. eliminates toxic pyruvate from the cell. - -d. links glycolysis with the citric
acid cycle.
-The citric acid cycle takes place in the:
a. outer mitochondrial membrane.
b. cytoplasm.
c. intermembrane space of mitochondria.
d. inner mitochondrial membrane.
e. mitochondrial matrix. - -e. mitochondrial matrix.
-A single molecule of glucose requires _____ "turn(s)" through the citric acid
cycle for its chemical energy to be completely harvested.
a. 1
b. 5
c. 3
d. 2
e. 4 - -d. 2
,-During the citric acid cycle:
a. ATP is synthesized by oxidative phosphorylation.
b. ATP is synthesized by substrate-level phosphorylation.
c. high-energy electrons are removed from NAD+ and FADH.
d. fuel molecules are completely reduced. - -b. ATP is synthesized by
substrate-level phosphorylation.
-During the citric acid cycle, the production of CO2 is the result of the _____
of intermediate compounds of the citric acid cycle coupled to the production
of _____.
a. oxidation; NADH
b. oxidation; GTP
c. reduction; ATP
d. oxidation; ATP
e. reduction; NADH - -a. oxidation; NADH
-What is the FINAL electron acceptor in the electron transport chain?
a. oxygen
b. glucose
c. ADP
d. ATP - -a. oxygen
-The proteins of the electron transport chain are:
a. located in the intermembrane space of mitochondria.
b. located in the mitochondrial matrix.
c. embedded in the outer mitochondrial membrane.
d. embedded in both mitochondrial membranes.
e. embedded in the inner mitochondrial membrane. - -e. embedded in the
inner mitochondrial membrane.
-Certain complexes of the mitochondrial electron transport chain pump
protons. Which of the following BEST describes the movement of protons in
this situation?
a. across the outer mitochondrial membrane, from the cytoplasm to the
intermembrane space
b. across the inner mitochondrial membrane, from the matrix to the
intermembrane space
c. across the inner mitochondrial membrane, from the intermembrane space
to the matrix
,d. across the outer mitochondrial membrane, from the intermembrane space
to the cytoplasm - -b. across the inner mitochondrial membrane, from the
matrix to the intermembrane space
-Protons in a mitochondrion flow through an ATP synthase from the:
a. matrix to the intermembrane space.
b. intermembrane space to the matrix.
c. intermembrane space to the cytoplasm.
d. cytoplasm to the intermembrane space. - -b. intermembrane space to the
matrix.
-Which of the following BEST describes how ATP synthase converts the
potential energy of the proton gradient to the chemical energy of ATP? Do
protons flow through the F0 or F1?
a. None of the other answer options is correct.
b. Kinetic energy from the flow of protons is stored in a new electrochemical
gradient within the F0 subunit. The potential energy of the electrochemical
gradient, in turn, is converted to kinetic energy in the F1 subunit and used to
catalyze ATP synthesis.
c. The flow of protons through the F0 subunit reduces the F1 subunit, which
allows ADP to be oxidized to ATP.
d. Kinetic energy from the flow of protons is converted to the kinetic energy
of rotation of the F0 subunit; the rotation of the F0 subunit leads to rotation
of the F1 subunit, which can then catalyze ATP synthesis.
e. The flow of protons through the F0 subunit oxidizes the F1 subunit, which
allows ADP to be reduced to ATP. - -d. Kinetic energy from the flow of protons
is converted to the kinetic energy of rotation of the F0 subunit; the rotation
of the F0 subunit leads to rotation of the F1 subunit, which can then catalyze
ATP synthesis.
-Fermentation takes place:
a. on the outer mitochondrial membrane.
b. in the cytoplasm.
c. in the mitochondrial matrix.
d. in the intermembrane space of mitochondria.
e. on the inner mitochondrial membrane. - -b. in the cytoplasm.
-During fermentation, pyruvate is:
a. carboxylated.
b. hydrogenated.
c. reduced.
d. phosphorylated.
, e. oxidized - -c. reduced
-Which of the following is the most important product of the fermentation
pathway in animal cells?
a. lactic acid
b. ATP
c. pyruvate
d. NAD+ - -d. NAD+
-In the absence of oxygen, fermentation:
a. None of the other answer options is correct.
b. regenerates NAD+ from the reduction of pyruvate.
c. generates ATP from the reduction of pyruvate.
d. regenerates NAD+ from the oxidation of pyruvate.
e. generates ATP from the oxidation of pyruvate. - -b. regenerates NAD+
from the reduction of pyruvate.
-Which of the following molecules would you expect to act as allosteric
activator of an enzyme in glycolysis?
a. ADP
b. NADP+
c. NADPH
d. pyruvate - -a. ADP
-We consume a variety of carbohydrates that are digested into a variety of
different sugars. How do these different sugars enter glycolysis?
a. All sugars are converted to fructose 6-phosphate and enter glycolysis at
phase 1, step 3.
b. All sugars are converted to glucose 6-phosphate and enter glycolysis at
phase 1, step 2.
c. Sugars are converted to various forms and enter glycolysis at various
stages.
d. All sugars are converted to glyceraldehyde 3-phosphate and enter
glycolysis at phase 3, step 6.
e. None of the other answer options is correct. - -c. Sugars are converted to
various forms and enter glycolysis at various stages
-Excess glucose is stored in large branched molecules of:
a. starch in bacteria.
b. glycogen and starch in both animals and plants.
c. starch in animals.
In eukaryotes, pyruvate oxidation takes place in the:
a. cytoplasm.
b. outer mitochondrial membrane.
c. inner mitochondrial membrane.
d. intermembrane space of mitochondria.
e. mitochondrial matrix. - -e. mitochondrial matrix
-When a single pyruvate is converted to acetyl-CoA, the other products of
the reaction are:
a. Pi and FADH2.
b. CO2 and ATP.
c. ATP and NADH.
d. FADH2 and ATP.
e. NADH and CO2. - -e. NADH and CO2
-Pyruvate oxidation is an important stage in cellular respiration because it:
a. generates ATP by substrate-level phosphorylation.
b. transfers large numbers of electrons to electron carriers.
c. is the first step in oxidative phosphorylation.
d. links glycolysis with the citric acid cycle.
e. eliminates toxic pyruvate from the cell. - -d. links glycolysis with the citric
acid cycle.
-The citric acid cycle takes place in the:
a. outer mitochondrial membrane.
b. cytoplasm.
c. intermembrane space of mitochondria.
d. inner mitochondrial membrane.
e. mitochondrial matrix. - -e. mitochondrial matrix.
-A single molecule of glucose requires _____ "turn(s)" through the citric acid
cycle for its chemical energy to be completely harvested.
a. 1
b. 5
c. 3
d. 2
e. 4 - -d. 2
,-During the citric acid cycle:
a. ATP is synthesized by oxidative phosphorylation.
b. ATP is synthesized by substrate-level phosphorylation.
c. high-energy electrons are removed from NAD+ and FADH.
d. fuel molecules are completely reduced. - -b. ATP is synthesized by
substrate-level phosphorylation.
-During the citric acid cycle, the production of CO2 is the result of the _____
of intermediate compounds of the citric acid cycle coupled to the production
of _____.
a. oxidation; NADH
b. oxidation; GTP
c. reduction; ATP
d. oxidation; ATP
e. reduction; NADH - -a. oxidation; NADH
-What is the FINAL electron acceptor in the electron transport chain?
a. oxygen
b. glucose
c. ADP
d. ATP - -a. oxygen
-The proteins of the electron transport chain are:
a. located in the intermembrane space of mitochondria.
b. located in the mitochondrial matrix.
c. embedded in the outer mitochondrial membrane.
d. embedded in both mitochondrial membranes.
e. embedded in the inner mitochondrial membrane. - -e. embedded in the
inner mitochondrial membrane.
-Certain complexes of the mitochondrial electron transport chain pump
protons. Which of the following BEST describes the movement of protons in
this situation?
a. across the outer mitochondrial membrane, from the cytoplasm to the
intermembrane space
b. across the inner mitochondrial membrane, from the matrix to the
intermembrane space
c. across the inner mitochondrial membrane, from the intermembrane space
to the matrix
,d. across the outer mitochondrial membrane, from the intermembrane space
to the cytoplasm - -b. across the inner mitochondrial membrane, from the
matrix to the intermembrane space
-Protons in a mitochondrion flow through an ATP synthase from the:
a. matrix to the intermembrane space.
b. intermembrane space to the matrix.
c. intermembrane space to the cytoplasm.
d. cytoplasm to the intermembrane space. - -b. intermembrane space to the
matrix.
-Which of the following BEST describes how ATP synthase converts the
potential energy of the proton gradient to the chemical energy of ATP? Do
protons flow through the F0 or F1?
a. None of the other answer options is correct.
b. Kinetic energy from the flow of protons is stored in a new electrochemical
gradient within the F0 subunit. The potential energy of the electrochemical
gradient, in turn, is converted to kinetic energy in the F1 subunit and used to
catalyze ATP synthesis.
c. The flow of protons through the F0 subunit reduces the F1 subunit, which
allows ADP to be oxidized to ATP.
d. Kinetic energy from the flow of protons is converted to the kinetic energy
of rotation of the F0 subunit; the rotation of the F0 subunit leads to rotation
of the F1 subunit, which can then catalyze ATP synthesis.
e. The flow of protons through the F0 subunit oxidizes the F1 subunit, which
allows ADP to be reduced to ATP. - -d. Kinetic energy from the flow of protons
is converted to the kinetic energy of rotation of the F0 subunit; the rotation
of the F0 subunit leads to rotation of the F1 subunit, which can then catalyze
ATP synthesis.
-Fermentation takes place:
a. on the outer mitochondrial membrane.
b. in the cytoplasm.
c. in the mitochondrial matrix.
d. in the intermembrane space of mitochondria.
e. on the inner mitochondrial membrane. - -b. in the cytoplasm.
-During fermentation, pyruvate is:
a. carboxylated.
b. hydrogenated.
c. reduced.
d. phosphorylated.
, e. oxidized - -c. reduced
-Which of the following is the most important product of the fermentation
pathway in animal cells?
a. lactic acid
b. ATP
c. pyruvate
d. NAD+ - -d. NAD+
-In the absence of oxygen, fermentation:
a. None of the other answer options is correct.
b. regenerates NAD+ from the reduction of pyruvate.
c. generates ATP from the reduction of pyruvate.
d. regenerates NAD+ from the oxidation of pyruvate.
e. generates ATP from the oxidation of pyruvate. - -b. regenerates NAD+
from the reduction of pyruvate.
-Which of the following molecules would you expect to act as allosteric
activator of an enzyme in glycolysis?
a. ADP
b. NADP+
c. NADPH
d. pyruvate - -a. ADP
-We consume a variety of carbohydrates that are digested into a variety of
different sugars. How do these different sugars enter glycolysis?
a. All sugars are converted to fructose 6-phosphate and enter glycolysis at
phase 1, step 3.
b. All sugars are converted to glucose 6-phosphate and enter glycolysis at
phase 1, step 2.
c. Sugars are converted to various forms and enter glycolysis at various
stages.
d. All sugars are converted to glyceraldehyde 3-phosphate and enter
glycolysis at phase 3, step 6.
e. None of the other answer options is correct. - -c. Sugars are converted to
various forms and enter glycolysis at various stages
-Excess glucose is stored in large branched molecules of:
a. starch in bacteria.
b. glycogen and starch in both animals and plants.
c. starch in animals.
