Learning Curve #7
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 _____.
oxidation; NADH
Which stage of cellular respiration occurs following production of pyruvate?
pyruvate oxidation
Acetyl-CoA synthesis occurs during:
pyruvate oxidation.
During the citric acid cycle: (a)ATP is synthesized by substrate-level phosphorylation. (b)ATP is synthesized by oxidative phosphorylation. (c)fuel molecules are completely reduced. (d)high-energy electrons are removed from NAD+ and FADH.
a
During what phase of glycolysis is NADH formed? (a)during phase 3, when glyceraldehyde 3-phosphate is phosphorylated (b)during phase 2, when glyceraldehyde 3-phosphate is formed (c)during phase 1, when glucose is phosphorylated (d)during phase 3, when pyruvate is finally formed (e)during phase 1, when fructose 1,6-biphosphate is formed
a
In cellular respiration, oxygen: (a)gains electrons and is reduced. (b)loses electrons and is oxidized. (c)gains electrons and is oxidized. (d)loses electrons and is reduced. (e)None of the other answer options is correct.
a
In glycolysis, ATP is synthesized by: (a)substrate-level phosphorylation. (b)redox reactions. (c)oxidative phosphorylation. (d)both substrate level and oxidative phosphorylation. (e)electron carriers.
a
In what organelle is pyruvate oxidation carried out in a cell? (a)mitochondrion (b)nucleus (c)chloroplast (d)Golgi apparatus (e)endoplasmic reticulum
a
The chemical bonds of carbohydrates and lipids have high potential energy because: (a)many of these bonds are C—C and C—H bonds, in which electrons are shared equally between atoms. (b)they are strong reducing agents. (c)they are strong oxidizing agents. (d)they are easy to phosphorylate. (e)many of these bonds are C—O bonds, in which electrons are not shared equally between atoms.
a
What happens when glucose is phosphorylated during phase 1 of glycolysis? (a)Glucose is destabilized so that it can be broken apart in phase 2. (b)It provides electrons to reduce FADH in phase 3. (c)It provides electrons to reduce NADH in phase 3. (d)ATP is produced. (e)Phosphorylated glucose enters the mitochondrion.
a
Which best describes how ATP synthase converts the potential energy of the proton gradient to the chemical energy of ATP? (a)Kinetic energy from the flow of protons is converted to the kinetic energy of rotation of the Fo subunit; the rotation of the Fo subunit leads to rotation of the F1 subunit, which can then catalyze ATP synthesis. (b)Kinetic energy from the flow of protons through the F0 subunit reduces the F1 subunit, which allows ADP to be oxidized to ATP. (c)Kinetic energy from 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 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.
a
Which of the following is a product (as opposed to a substrate) of at least one of the processes of cellular respiration? (a)water (b)oxygen (c)glucose
a
Most of the proteins of the electron transport chain are:
embedded in the inner mitochondrial membrane.
(T/F) Fermentation produces nearly twice as much ATP as aerobic respiration, which explains why it is a preferred pathway for bacteria.
False
(T/F) In a plant cell, the oxidative phosphorylation stage of cellular respiration is carried out in the cytoplasm.
False
(T/F)Pyruvate oxidation produces a large amount of ATP through substrate-level phosphorylation.
False
(T/F)The glycolysis stage is responsible for producing most of the ATP during cellular respiration.
False
ATP is not generated directly in the citric acid cycle. Instead, an intermediate is first generated by substrate-level phosphorylation. The intermediate is:
GTP.
(T/F) Both NAD+ and molecular oxygen serve as electron acceptors in cellular respiration.
True
(T/F)The ATP produced during glycolysis is the result of substrate-level phosphorylation.
True
In cellular respiration, glucose is _____ to CO2 and oxygen is _____ to water. (a)phosphorylated; deoxygenated (b)oxidized; reduced (c)reduced; oxidized (d)deoxygenated; phosphorylated (e)oxidized; oxidized
b
What product of the pyruvate oxidation stage of cellular respiration will have the two electrons that are lost from pyruvate? (a)acetyl-CoA (b)NADH (c)NAD+ (d)CO2 (e)coenzyme A
b
Which statement is true regarding triacylglycerols? (a)Each molecule of triacylglycerol yields less ATP than a molecule of glucose. (b)The fatty acids from triacylglycerols are broken down to generate acetyl-CoA. (c)ATP is derived from triacylglycerols, mostly from substrate-level phosphorylation. (d)The fatty acids from triacylglycerols are metabolized by glycolysis. Incorrect: Like glycogen, triacylglycerols are stored primarily in the liver. (e)Like glycogen, triacylglycerols are stored primarily in the liver.
b
At the end of glycolysis, the carbon originally found in the starting glucose molecule is now present in: (a)four ATP molecules and two pyruvate molecules. (b)two NADH molecules and two pyruvate molecules. (c)two pyruvate molecules. (d)two ATP molecules and two NADH molecules. (e)one pyruvate molecule.
c
During which phase(s) of glycolysis do we observe pyruvate production, ATP synthesis, and reduction of NAD+? (a)preparatory phase and cleavage phase (b)preparatory phase (c)payoff phase (d)cleavage phase (e)preparatory phase, cleavage phase, and payoff phase
c
Excess glucose is stored in large branched molecules of: (a)starch in animals. (b)glycogen and starch in both animals and plants. (c)glycogen in animals. (d)glycogen in plants. (e)starch in bacteria.
c
The storage carbohydrate in animals is ___________ and in plants is __________. (a)lactose; glucose (b)starch; glycogen (c)glycogen; starch (d)triacyl-glycerol; cellulose (e)triacyl-glycerol; starch
c
Although glycolysis produces four molecules of ATP by substrate-level phosphorylation, the net gain of ATP for the cell is two molecules. This is because: (a)some ATP is used to power the mitochondria. (b)six molecules are consumed in the initial reactions. (c)two molecules are used in the second stage. (d)two molecules are used in the initial stage.
d
Due to the pumping action of the electron transport chain, protons have a high concentration in the _____ and a low concentration in the _____. (a)mitochondrial matrix; extracellular fluid (b)mitochondrial matrix; cytoplasm (c)mitochondrial matrix; intermembrane space (d)intermembrane space; mitochondrial matrix
d
Which of the following is a net product of glycolysis? (a)2 NAD+ (b)2 CO2 (c)4 ATP (d)2 pyruvate (e)2 acetyl-CoA
d
A simplified overall equation for respiration is as follows: C6H12O6 + 6O2 →6CO2+ 6H2O + energy In this reaction, we can say that _____ is reduced and _____ is oxidized. (a)glucose; carbon dioxide (b)carbon dioxide; water (c)water; glucose (d)water; oxygen (e)oxygen; glucose
e
Glycolysis is: (a)aerobic in some tissues but anaerobic in others. (b)aerobic in some organisms but anaerobic in others. (c)None of the other answer options is correct. (d)aerobic. (e)anaerobic.
e
In eukaryotic cells, glycolysis occurs in: (a)vacuoles. (b)the endoplasmic reticulum. (c)the matrix of the mitochondria. (d)the nucleus. (e)the cytoplasm.
e
When a single pyruvate is converted to acetyl-CoA during pyruvate oxidation, the other products of the reaction are: (a)FADH2 and ATP. (b)CO2 and ATP. (c)ATP and NADH. (d)Pi and FADH2. (e)NADH and CO2.
e
Which of the following is an electron carrier in its reduced form? (a)ADP (b)ATP (c)NAD+ (d)Pi (e)NADH
e
Proteins can be broken down to extract energy. They are typically broken down into amino acids, which then enter cellular respiration via:
glycolysis or the citric acid cycle.
On completion of either ethanol or lactic acid fermentation, the yield is only two ATP molecules per glucose molecule. The remaining chemical energy from the glucose is found primarily in:
lactic acid and ethanol.
Of the 6 carbons in a starting molecule of glucose, at the completion of pyruvate oxidation, _____ carbons are fully oxidized to _____, while _____ carbons remain in _____.
two; CO2; four; acetyl groups
