Biology Honors
Cellular Respiration ~ Chapter 7 Study Guide
1. What happens to electrons as they are transported along the electron transport chain?
a) they lose energy
b) they gain energy
c) they are pumped into the space between the inner and outer mitochondrial membranes
d) they combine with O2 and protons to form water
2. ATP
a) contains five phosphate groups
b) is essential for a cell to perform all the task necessary for life
c) is found only in bacteria
d) All of the above
3. The electron transport chain is driven by two products of the Krebs cycle:
a) oxaloacetic acid and citric acid
c) NADH and FADH2
b) H2O and CO2
d) acetyl CoA and ATP
4. In the first step of aerobic respiration, pyruvic acid from glycolysis produces CO 2, NADH, H+, and
a) citric acid
b) acetyl CoA
c) oxaloacetic acid
d) lactic acid
5. Energy is released from ATP when the bond is broken between
a) two phosphate groups
c) ribose and a phosphate group
b) adenine and ribose
d) adenine and a phosphate group
6. Glycolysis uses energy from two molecules of ATP but forms ___ molecules of ATP.
a) two
b) three
c) four
d) eight
7. Which is a product in the aerobic breakdown of a glucose molecule?
a) water
b) oxygen
c) light
d) alcohol
8. An important molecule generated by both lactic acid and alcoholic fermentation is
a) ATP
b) NADH
c) CO2
d) NAD+
9. When cells break down food molecules, energy
a) is released all at once
b) is released entirely as body heat into the environment
c) is temporarily stored in ATP molecules
d) causes excitation in electrons in chlorophyll molecules
10. The final electron acceptor in the electron transport chain is
a) O2
b) CO2
c) pyruvic acid
d) water
11. Which of the following is the best explanation for the presence of both chloroplasts and mitochondria
in plant cells?
a) In the light, plants are photosynthetic autotrophs. In the dark, they are heterotrophs.
b) If plants cannot produce enough ATP in the process of photosynthesis to meet their energy needs,
they can produce it in aerobic respiration.
c) Sugars are produced in chloroplasts. These sugars can be stored in the plant for later use, converted to
other chemicals, or broken down in aerobic respiration to yield ATP for the plant to use to meet its
energy needs.
d) The leaves and sometimes the stems of plants contain chloroplasts, which produce ATP to meet
energy needs of these parts. The roots of plants contain mitochondria which produce ATP to meet
the energy needs of these plant parts.
12. The net number of ATP molecules made directly by glycolysis is
a) 2
b) 6
c) 32
d) 38
13. Which of the following is not a product of the Krebs cycle
a) ATP
b) ethyl alcohol
c) CO2
d) FADH2
14. By accepting electrons and protons, the oxygen used in aerobic respiration turns into
a) CO2
b) H2O
c) C6H12O6
d) ATP
15. The term "aerobic" in aerobic processes means the process requires
a) ATP
b) oxygen
c) carbon monoxide
d) lactic acid
16. The anaerobic process of splitting glucose and forming two molecules of pyruvic acid is called
a) fixation
b) fermentation
c) lactic acid
d) glycolysis
17. In the _______ acetyl-CoA combines with a 4-carbon molecule to form a 6-carbon molecule.
a) Krebs cycle b) electron transport chain
c) Calvin cycle d) thylakoid membranes
18. The process by which food molecules are broken down to release energy is called
a) fermentation
b) respiration
c) transpiration
d) digestion
19. The two end products of alcoholic fermentation are
a) ethyl alcohol and pyruvic acid
c) carbon dioxide and glucose
b) ethyl alcohol and carbon dioxide
d) pyruvic acid and glucose
20. Lactic acid fermentation forms lactic acid from
a) carbon dioxide
b) pyruvic acid
c) sodium hydroxide
d) citric acid
21. The anaerobic pathways provide enough energy to meet all of the energy needs of
a) all organisms
c) all unicellular and most multicellular organisms
b) no organisms
d) many unicellular and some multicellular organisms
22. Glycolysis takes place
a) in the cytosol
b) in the mitochondria
c) only if oxygen is present
d) only if oxygen is absent
23. The process of glycolysis and anaerobic pathways is called
a) aerobic respiration
b) fermentation
c) glycolysis
d) cytosol
24. The product of acetyl CoA and oxaloacetic acid is
a) NAD+
b) kilocalorie
c) citric acid
d) fermentation
25. The location of electron transport chain in prokaryotes
a) cytosol
b) mitochondria
c) nucleus
d) cell membrane
26. Yeast produce alcohol and CO2 in the process of
a) lactic acid fermentation
c) alcoholic fermentation
b) aerobic respiration
d) glycolysis
27. What is the process by which glucose is converted to pyruvic acid
a) electron transport
b) aerobic respiration
c) glycolysis
d) photosynthesis
28. The electron transport chain of aerobic respiration
a) generates O2 from H2O
b) produces NADH by chemiosmosis
c) pumps electrons into the mitochondrial matrix
d) pumps protons into the space between the inner and outer mitochondrial membranes
29. In cellular respiration, the most energy is transferred in which step?
a) glycolysis
b) electron transport chain
c) Krebs cycle
d) fermentation
30. The conversion of pyruvic acid to carbon dioxide and ethanol is called
a) lactic acid fermentation b) alcoholic fermentation c) gasohol conversion
d) glycolysis
31. Both lactic acid and alcoholic fermentation produce
a) a two-carbon molecule from a six-carbon molecule
b) CO2 from a three-carbon molecule
c) ATP from ADP and phosphate
d) NAD+ from NADH and H+
32. In alcoholic fermentation, ethyl alcohol is produced from
a) NAD+
b) NADH
c) lactic acid
d) pyruvic acid
33. A reactant in glycolysis is
a) ethyl alcohol
b) glucose
c) pyruvic acid
d) lactic acid
34. The Krebs cycle
a) releases two molecules of CO2
b) produces a six-carbon molecule from six molecules of CO2
c) produces NAD+ from NADH and H+
d) generates most of the ATP produced in aerobic respiration
35. The breakdown of organic compounds to produce ATP is known as
a) cellular respiration
c) alcoholic fermentation
b) lactic acid fermentation
d) photosynthesis
36. Glycolysis begin with glucose and produces
a) PGAL
b) lactic acid
c) acetyl CoA
d) pyruvic acid
37. The starting substance of the Krebs cycle, which is regenerated at the end of the cycle, is
a) acetyl CoA
b) pyruvic acid
c) oxaloacetic acid
d) citric acid
38. In the first step of aerobic respiration, pyruvic acid binds to a molecule called
a) acetyl-CoA
b) NADH
c) ATP
d) coenzyme A (CoA)
39. Which of the following is an electron acceptor?
a) cytosol
b) NAD+
c) citric acid
d) cell membrane
40. The first pathway of cellular respiration is called
a) fermentation
b) aerobic respiration
c) glycolysis
d) anaerobic respiration
41. The Krebs cycle takes place in the
a) cytosol
b) mitochondrial matrix
d) outer membrane
c) cristae
42. Glycolysis and oxidative respiration are different in that
a) glycolysis occurs on the cell membrane, while oxidative respiration occurs in mitochondria
b) glycolysis occurs only in photosynthesis, while oxidative respiration is part of cellular respiration
c) glycolysis occurs in the absence of oxygen, while oxidative respiration requires oxygen
d) both of these terms are different names for the same process
43. The energy efficiency of aerobic respiration (including glycolysis) is approximately
a) 7 %
b) 50 %
c) 66 %
d) 100 %
44. Most eukaryotic cells produce only about ___ ATP molecules per molecule of glucose.
a) 2
b) 6
c) 18
d) 36
45. You have been growing some animal cells in culture. The cells grow well for several weeks, and then
don't seem to grow as well. You conduct some tests and determine that there is a lot of lactic acid in the
culture fluid. Which of the following is the most likely the explanation for the poor conditions of the cells?
a) There is too much glucose in the culture fluid
c) There is not enough glucose in the
culture fluid
b) There is too much oxygen in the culture fluid
d) There is not enough oxygen in the
culture fluid
TRUE OR FALSE
*** Explain why the false answers are false.
46. In aerobic respiration, glucose molecules are converted into acetyl CoA molecules when they enter the
Krebs cycle.
47. Plants cannot carry out cellular respiration.
48. Yeasts produce alcohol and CO2 in the process of lactic-acid fermentation.
49. Fermentation and oxidative respiration both take place in the absence of oxygen.
50. In cellular respiration, glycolysis follows the Krebs cycle.
51. Glycolysis is an aerobic process that breaks down food molecules to produce energy.
52. Lactic acid fermentation is an anaerobic process.
53. Muscle cells produce alcohol and CO2 in the process of lactic acid fermentation.
54. In cellular respiration, more energy is transferred in the electron transport chain than in any other step.
1. Draw and label a mitochondrion and explain where each stage of aerobic respiration occurs.
2. Under what conditions would cells in your body undergo lactic-acid fermentation?
3. How does aerobic respiration ultimately depend on photosynthesis?
4. The diagram below depicts the stages of fermentation. Complete the diagram by writing the names of
the pathways in the ovals and the names of the molecules in the boxes.
5. The diagram below summarizes the electron transport chain and chemiosmosis in aerobic respiration.
Label the substances that are transported along the arrows labeled a–d in the spaces provided. Label the
reactants or products that are represented by e–g in the spaces provided.
6. Use the following terms and phrases to complete the concept map below.
anaerobic process
glycolysis
oxygen
electron transport chain
Krebs cycle
pyruvic acid
glucose