49) In fermentation, ________ is ________.
A) NADH; reduced
B) NAD+; oxidized
C) NADH; oxidized
D) ethanol; oxidized
50) When an organism such as a yeast lives by fermentation, it converts the pyruvate from
glycolysis into a different compound, such as alcohol. Why doesn’t it secrete the pyruvate
directly?
A) The conversion yields 32 ATP per pyruvate molecule.
B) The conversion yields one NADH per pyruvate molecule.
C) The conversion is needed to regenerate the molecules needed for glycolysis.
D) A buildup of pyruvate in the surrounding environment would be too toxic.
51) A child is born with a rare disease in which mitochondria are missing from skeletal muscle
cells. However, the muscles still function. Physicians find that
A) the muscles contain large amounts of lactate following even mild physical exercise.
B) the muscles contain large amounts of carbon dioxide following even mild physical exercise.
C) the muscles require extremely high levels of oxygen to function.
D) the muscle cells cannot split glucose to pyruvate.
52) Some friends are trying to make wine in their basement. They’ve added yeast to a sweet
grape juice mixture and have allowed the yeast to grow. After several days they find that sugar
levels in the grape juice have dropped, but there’s no alcohol in the mixture. The most likely
explanation is that
A) the mixture needs more sugar because yeast need a lot of energy before they can begin to
produce alcohol.
B) the mixture needs less oxygen because yeast only produce alcohol in the absence of oxygen.
C) the mixture needs more oxygen because yeast need oxygen to break down sugar and get
enough energy to produce alcohol.
D) the yeast used the alcohol as a carbon source.
53) In yeast cells,
A) lactic acid is produced during anaerobic respiration.
B) lactic acid is produced during glycolysis.
C) alcohol is produced during the citric acid cycle.
D) alcohol is produced after glycolysis.
54) Bacteria that are unable to survive in the presence of oxygen are called
A) obligate anaerobes.
B) obligate aerobes.
C) facultative anaerobes.
D) aerotolerant anaerobes.
55) Yeasts can produce ATP by either fermentation or oxidative phosphorylation; thus, they are
A) strict anaerobes.
B) strict aerobes.
C) facultative anaerobes.
D) facultative aerobes.
56) When did the level of oxygen in Earth’s atmosphere become high enough to sustain aerobic
respiration?
A) 1.0 billion years ago
B) 1.5 billion years ago
C) 2.7 billion years ago
D) 3.5 billion years ago
57) Which of the following statements regarding glycolysis is false?
A) Glycolysis is considered to be an ancient metabolic process because it does not require
oxygen.
B) Glycolysis is considered to be an ancient metabolic process because it is not located in a
membrane-bound organelle.
C) Glycolysis is considered to be an ancient metabolic system because it occurs universally.
D) Glycolysis is considered to be an ancient metabolic system because it is the most efficient
metabolic pathway for ATP synthesis.
58) To obtain energy from starch and glycogen, the body must begin by
A) hydrolyzing the starch to glucose and the glycogen to amino acids.
B) hydrolyzing both starch and glycogen to glucose.
C) converting both starch and glycogen to fatty acids.
D) removing one glucose at a time with a condensation reaction.
59) When proteins are used as a source of energy for the body, the proteins
A) are converted into glucose molecules, which are fed into glycolysis.
B) are converted mainly into intermediates of glycolysis or the citric acid cycle.
C) donate electrons directly to the electron transport chain.
D) are hydrolyzed to glucose and converted to acetyl CoA, which enters the citric acid cycle.
60) When a cell uses fatty acids for aerobic respiration, it first hydrolyzes fats to
A) glycerol and amino acids.
B) glycerol and fatty acids.
C) fatty acids and sugars.
D) sugars and glycerol.
61) If you consume 1 g of each of the following, which will yield the most ATP?
A) fat
B) glucose
C) protein
D) starch
62) Which of the following statements regarding food is false?
A) Food provides the raw materials for biosynthetic pathways that make molecules for cellular
repair and growth.
B) Food provides the raw materials for biosynthetic pathways that can produce molecules that
are not actually present in the original food.
C) Food provides the raw materials for biosynthetic pathways that can produce sugar by a
process that is the exact opposite of glycolysis.
D) Food provides the raw materials for biosynthetic pathways that consume ATP.
63) Which of the following organisms can make organic molecules from water and carbon
dioxide?
A) bear
B) mushroom
C) wheat
D) crayfish
64) The conversion of CO2 and H2O into organic compounds using energy from light is called
A) glycolysis.
B) photosynthesis.
C) fermentation.
D) cellular respiration.
65) If ATP accumulates in a cell,
A) the cell receives a signal that there is a need for more energy.
B) feedback inhibition speeds up cellular respiration.
C) feedback inhibition slows down cellular respiration.
D) the rate of cellular respiration does not change.
66) The antibiotic oligomycin works by inhibiting ATP synthase. You would expect that
A) there will be an increase in ATP production.
B) H+ will accumulate in the intermembrane space.
C) H+ will accumulate in the mitochondrial matrix.
D) NAD+ and FAD will pick up the extra H+.
67) The Pasteur effect shows that yeast consume glucose at a higher rate under anaerobic
conditions than under aerobic conditions. Which of the following statements correctly explains
this observation?
A) Yeast are obligate anaerobes, so aerobic conditions will kill yeasts.
B) Yeast are photosynthetic, so they are able to produce their own oxygen.
C) Less ATP is made under anaerobic conditions, so more glucose must be consumed to produce
an equivalent amount of ATP.
D) This observation is incorrect. Aerobic conditions mean that cells make more ATP and use
more glucose.
68) DNP is a chemical that has been used by people to lose weight. However, it is a dangerous
option and has caused several people to die. DNP works in a fashion similar to that of brown fat.
Based on this information, how would DNP cause weight loss and death?
A) DNP must prevent food from being consumed aerobically, so cells instead perform
fermentation, and lactate buildup is deadly.
B) DNP must increase the rate of substrate-level phosphorylation, causing NADH to be produced
more quickly than it can be used by the electron transport chain.
C) DNP must block cells from using fats and proteins to make ATP.
D) DNP must increase metabolism of food by producing heat instead of ATP.
69) A friend tells you that he is going on a low-carb diet to lose weight because he thinks that
carbs contain more energy than fats or protein. What would you tell your friend about his plan?
A) This is a good idea because sugars enter the fuel breakdown pathway earlier than other food
molecules.
B) This is a good idea because sugars have more electrons than fats and protein.
C) This is an incorrect idea because fats contain more hydrogen atoms than carbohydrates and
protein.
D) This is an incorrect idea because all food molecules store the same amount of energy.
70) Marathon runners are long-distance runners (marathons are races that are 26.2 miles long).
Studies have shown that the muscles of marathon runners contain an abundance of slow-twitch
fibers. Which of the following statements about these fibers is true?
A) Slow-twitch fibers have lots of mitochondria to make ATP aerobically.
B) Slow-twitch fibers have lots of mitochondria to make ATP through fermentation.
C) Slow-twitch fibers have few mitochondria and make ATP aerobically.
D) Slow-twitch fibers have few mitochondria and make ATP through fermentation.
71) Wood frogs freeze solid during the winter and then thaw in the spring. As the freezing
progresses, blood circulation stops. How would you expect cells not being served by the
circulatory system to produce ATP during this time, and what by-product would you expect to
build up in the cells?
A) aerobic respiration and CO2
B) fermentation and lactate
C) fermentation and alcohol
D) photosynthesis and O2
72) Arsenic is a poison that binds to a molecule needed to build acetyl CoA. Based on this
information, which part of cellular respiration would be stopped if arsenic were ingested?
A) glycolysis
B) citric acid cycle
C) electron transport chain
D) ATP synthase
73) NADH pills can be purchased over the counter and are often taken by sufferers of chronic
fatigue syndrome (CFS). How might these pills benefit a CFS patient?
A) They would increase energy by creating more FADH2.
B) They would decrease the rate of glycolysis.
C) They would increase the number of electrons provided to the electron transport chain.
D) They would decrease the rate of alcoholic fermentation.
74) NADH is also used by cells when making certain molecules. Based on your knowledge of
NADH’s role in cellular respiration, what do you think NADH’s role is in biosynthesis of
molecules?
A) oxidizing molecules
B) reducing molecules
C) phosphorylating molecules
D) dehydrating molecules
75) Which of the following statements about the energy yield of aerobic respiration is false?
A) Glycolysis resulting from 1 glucose molecule yields 2 ATP molecules.
B) The oxidation of pyruvate results in the production of 0 ATP molecules
C) Oxidative phosphorylation resulting from 1 glucose molecule yields 12 ATP molecules.
D) The citric acid cycle resulting from 1 glucose molecules yields 2 ATP molecules.
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6.2 Art Questions
1) Which step of the citric acid cycle requires both NAD+ and ADP as reactants?
A) step 1
B) step 2
C) step 3
D) step 4
22
2) Which H+ has just passed through the inner mitochondrial membrane by diffusion?
A) hydrogen ion A
B) hydrogen ion B
C) hydrogen ion C
D) hydrogen ion D
After reading the paragraph below, answer the questions that follow.
Most bats are inactive during the day (this is known as torpor) and feed during the night. The
graph below shows hypothetical data for a bat species.
3) Based on this graph, what is the relationship between metabolic rate and body temperature?
A) When metabolic rate drops, so does body temperature.
B) When metabolic rate drops, body temperature rises.
C) When metabolic rate drops, body temperature remains constant.
D) There is no relationship between metabolic rate and body temperature.
4) Why does the relationship between metabolic rate and temperature exist?
A) Cellular respiration requires organisms to take in heat energy.
B) A by-product of cellular respiration is heat.
C) Cellular respiration causes the body to cool because all the energy is used to make ATP.
D) There is no relationship between metabolic rate and body temperature.
5) Bats contain brown fat between their shoulder blades. How could this brown fat be an
adaptation to torpor?
A) Brown fat has many mitochondria, so it can produce more ATP.
B) Brown fat can produce heat and ATP through fermentation.
C) The mitochondria in brown fat can produce heat without making ATP.
D) It is not an adaptation; white fat is what they need to produce heat.
6.3 Scenario Questions
After reading the paragraph below, answer the questions that follow.
As a scientist employed by the FDA, you’ve been asked to sit on a panel to evaluate a
pharmaceutical company’s application for approval of a new weight loss drug called Fat Away.
The company has submitted a report summarizing the results of their animal and human testing.
In the report, it was noted that Fat Away works by affecting the electron transport chain. It
decreases the synthesis of ATP by making the mitochondrial membrane permeable to H+, which
allows H+ to leak from the intermembrane space to the mitochondrial matrix. This effect leads to
weight loss.
1) Fat Away prevents ATP from being made by
A) destroying the H+ gradient that allows ATP synthase to work.
B) preventing glycolysis from occurring.
C) preventing the conversion of NADH to NAD+.
D) slowing down the citric acid cycle.
2) You predict that a side effect of Fat Away will be
A) increased production of NADH.
B) increased production of pyruvate.
C) increased production of lactate.
D) increased body temperature.