Cellular Respiration and Harvesting Chemical Energy

Which of the following statements is TRUE of fermentation?
1. It produces a net gain of ATP.
2. It produces a net gain of NADH.
3. It is an aerobic process.
4. It can be performed only by bacteria.
5. It produces more energy per glucose molecule than does aerobic respiration.
The following statements compare combustion with the aerobic respiration of glucose. Which is FALSE?
1. Combustion releases more total energy from flucose than does respiration.
2. Combustion releases evergy from glucose at a more rapid rate than does respiration.
3. Combustion releases nearly all energy as heat and light; respiration captures come of the energy in chemical bonds.
4. Combustion uses heat to provide activation energy; respiration uses enzymes to lower activation energy.
5. Combustion involves the direct transfer of hydrogen atoms to oxygen; respiration uses an indirect transfer of hydrogens.
Glycolysis is believed to be one of the most ancient of metabolic processes. Which statement below LEAST supports this idea?
1. If run in reverse, glycolysis will build glucose molecules.
2. Glycolysis neither uses nor needs oxygen.
3. Glycolysis is found in all eukaryotic cells.
4. The enzymes of glycolysis are found in the cytosol rather than in a membrane-enclosed organelle.
5. Bacteria, the most primitive of cells, make extensive use of glycolysis.
Which of the following statements about lactate fermentation is FALSE?
1. Lactate fermentation produces ATP molecules in addition to the few produced by glycolysis.
2. Lactate fermentation oxidezies NADH to NAH+ and keeps glycolysis functioning.
3. Lactate fermentation takes place in vigorously exercised muscle cells.
4. Lactate fermentation can take place under anaerobic conditions.
5. Lactate fermentation in muscle cells often creates a need for oxygen that must be satisfied later.
Which kind of metabolic poison would most directly interfere with glycolysis?
1. An agent that reacts with oxygen and depletes its concentration in the cell.
2. An agent that binds to pyruvate and inactiviates it.
3. An agent that closely mimics the structure of glucose but is nonmetabolic.
4. An agent that reacts with NADH and oxidizes it to NAD+
5. An agent that inhibits the formation of actyl coenzyme A.
All of the following statements about glycolysis are true EXCEPT:
1. Glycolysis has steps involving oxidation-reduction reactions.
2. The enzymes of glycolysis are located in the cytosol of the cell.
3. Glycolysis can operate in the complete absence of oxygen.
4. The end product of glycolysis are carbon dioxide and water.
5. Glycolysis makes ATP exclusively through substrate-level phosphorylations.
Which of the following statements about NAD+ is FALSE?
1. NAD+ is reduced to NADH during both glycolysis and the Krebs cycle.
2. NAD+ has more chemical energy than NADH.
3. NAD+ is reduced by the action of dehydrogenases.
4. NAD+ can receive electrons for use in oxidative phophorylation.
5. In the absence of NAD+, glycolysis cannot function.
Which metabolic process is most closely associated with intracellular membranes?
1. substrate-level phosphorylation
2. oxidative phosphorylation
3. glycolysis
4. the Krebs cycle
5. ethanolic fermentation
Pyruvate is the last product of glycolysis. Which statement below is TRUE?
1. There is more energy in 6 molecules of carbon dioxide than in 2 molecules of pyruvate.
2. There is more energy in pyruvate than in lactate.
3. There is less energy intow molecules of pyruvate than in one molicule of glucose.
4. Pyruvate is in a more oxidized state than carbon dioxide.
5. Pyruvate is in a more reduced state than glucose.
During oxidative phosphorylation, water is formed. Where do the oxygen atoms in the water come from?
1. carbon dioxide
2. glucose
3. molecular oxygen
4. pyruvate
5. lactate
What does chemiosmosis involve?
1. The diffusion of water down an electochemical gradient that drives ATP synthesis.
2. A proton gradient that drives the redox reactions of electron transport.
3. A proton-motive force that drives the synthesis of ATP
4. An ATP synthase that pumps protons across the inner mitochondiral membrane.
5. The uptake of NADH produced in glycolysis into the mitochondrion
Muscle cells in oxygen deprivation convert pyruvate to __________ and in this step gain ____________.
1. lactate; ATP
2. alcohol: carbon dioxide
3. alcohol; ATP
4. ATP; NAD+
5. lactate; NAD+
Phosphofructokinase is an important control enzyme. Which of the following statements concerning this enzyme is FALSE?
1. It is activated by citrate.
2. It is inhibited by ATP.
3. It is activated by ADP.
4. It is a coordinator of the processes of glycolysis and the Krebs cycle.
5. It is an alosteric enzyme.
Which type of enzyme in cellular respiration is primarily responsible for removing electons from organic molecules?
1. decarboxylase
2. ATP synthase
3. deaminase
4. dehydrogenase
5. phophofructokinase
Why is it impossible to quantify the amount of ATP derived from each glucose during cellular respiration?
1. The mitochondria are too unstable.
2. The proton gradient is used for many purposes.
3. ATP is used up as soon as it is produced.
4. The ATP remains inside the mitochondira.
Assume that a eukaryotic cell has abundant glucose and oxygen, but needs ATP. The proton gradient in mitochondria of this cell will be generated by _______________ and use primarily for ________________.
1. the electon transport chain; ATP synthesis
2. the electron transport chain; substrate-level phosphorylation
3. glycolysis; production of water
4. fermentation; NAD reduction
5. diffusion of protons; ATP synthesis
Which proces in eukaryotic cells will normally proceed whether oxygen is present or absent?
1. electon transport
2. glycolysis
3. Krebs cycle
4. oxidative phosphrylation
The direct energy source that drives ATP synthesis during respiratory oxidative phosphorylation is
1. oxidation of glucose to carbon dioxide and water
2. the thermodynamically favorable flow of electons from NADH to the mitochondrial electron transport carriers.
3. the final transfer of electons to oxygen.
4. the difference in H+ concentrations on opposite sides of the inner mitochondrial membrane.
5. thermodynamically favorable transfer of phosphate from glycolysis an dKrebs cycle intermediate molecules of ADP
DNP is a molecule that causes membranes to become more permeable to H+. What would you expect to happen to an animal that is given an injecton of this substance and kept on the same diet throughout the experiment?
1. It woudl become hyperactive.
2. It would have a lower body temperature.
3. It would lose weight.
4. Its metabolic rate would decrease.
5. It would produce excess amounts of ATP.
The primary function of the mitochondrion is the production of ATP. To carry out this function, the mitochondrion must have all of the following EXCEPT:
1. the membrane-bound electron transport chain
2. proton pumps embedded in the inner membrane
3. enzymes for glycoysis.
4. enzymes for the Krebs cycle.
5. mitochondrial ATP synthase
A major function of the mitochondrial inner membrane is the conversion of energy from electons to the stred energy of the phosphate bond in ATP. To accomplish this function, this membrane must have all of the following features EXCEPT:
1. proteins to accept electrons from NADH
2. intefral, transverse ATP synthase
3. proton pumps embedded in the membrane
4. the electron transport chain of proteins
5. high permeability to protons
If citric acid has six carbon atoms, how many carbon atoms does succinic acid have?
1. 1
2. 4
3. 5
4. 6
5. 12
Starting with one Acetyl CoA molecule, what is the maximum number of ATP molecules that could be made through substrate-level phosphorylation?
1. 1
2. 2
3. 11
4. 12
5. more than 20
Carbon skeletons for amino acid biosynthesis are supplied by intermediates of the Kreb cycle. Which intermediate would supply the carbon skeleton for synthesis of a 5-carbon amino acid?
1. citric acid
2. alpha-ketoglutaric acid
3. succinic acid
4. malic acid
Which reaction shows a split of one molecule into two smaller molecules?
1. Oxidative phosphorylation
2. Glycolysis
3. Phosphorylation
4. Krebs cycle
Fermentation is not as energy productive as respiration because
1. it does not take place in a specialized membrane-enclosed organelle.
2. pyruvate is more reduced than carbon dioxide; it still contains much of the energy from glucose.
3. it takes place within the mitochondria of cells.
4. it is the pathway common to fermentation and respiration.
5. NAD+ is regenerated by other kinds of fermentation, without the electrons passing through the electron transport chain.
The oxygen consumed during cellular respiration is directly involved in
1. glycolysis
2. accepting electrons at the end of the electron transport chain.
3. the citric acid cycle.
4. the oxidation of pyruvate to acetyl CoA
5. the phophorylation of ADP
The ATP made during fermentation is generated by which of the following?
1. substrate-level phosphorylation
2. electron transport
3. photophosphorylation
4. chemiosmosis
5. oxidation of NADH
All of the following substances are produced in a muscle cell under anaerobic conditions EXCEPT:
1. ATP
2. pyruvate
3. lactate
4. acetyl CoA
5. NADH
In addition to ATP, what are the end products of glycolysis?
1. Carbon dioxide and water
2. Carbon dioxide and ethyl alcohol
3. NADH and pyruvate
4. Carbon dioxide and NADH
5. Water and ethyl alcohol
The Krebs cycle produces which of the following molecules that then transfer energy to the electron transport system?
1. ATP and Carbon dioxide
2. Carbon dioxide and FAD
3. FADH2 and NADH
4. NADH and ATP
5. NADH, FADH2 and ATP
Catabolism of proteins, lipids and carbohydrates can result in a 2-carbon molecule that enters the Krebs cycle. What is the molecule?
1. glucose
2. acetic acid or acetyl CoA
3. a fatty acid
4. an amino acid
5. pyruvate
In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP?
1. energy released as electrons flow through the electron transport system.
2. energy released from substrate-level phosphorylation.
3. energy released from ATP synthase pumping hydrogen ions against their concentration gradient.
4. energy released from movement of protons through ATP synthase.
5. No external source of energy is required because the reaction is exergonic.
Suppose a yeast cell uses 10 moles of glucose for energy production. No oxygen is available. What will be the maximum net yield of ATP in moles.
1. 12
2. 15
3. 20
4. 30
5. 36
How many carbon atoms can each pyruvic acid feed into the Krebs cycle?
1. 2
2. 4
3. 6
4. 8
5. 10
A. Stage 1: glycolysis
B. Stage 2: oxidation of pyruvate to acetyl CoA
C. Stage 3: Krebs cycle
D: Stage 4: oxidative phosphorylation (chemiosmosis)

Which of the stages produces the most ATP when glucose is completely oxidized to carbon dioxide?
1. A.
2. B
3. C.
4. D.
A. Stage 1: glycolysis
B. Stage 2: oxidation of pyruvate to acetyl CoA
C. Stage 3: Krebs cycle
D: Stage 4: oxidative phosphorylation (chemiosmosis)

Which one of the stages normally occurs whether or not oxygen is present?
1. A.
2. B.
3. C.
4. D.
A. Stage 1: glycolysis
B. Stage 2: oxidation of pyruvate to acetyl CoA
C. Stage 3: Krebs cycle
D: Stage 4: oxidative phosphorylation (chemiosmosis)

Which one of the stages occurs in the cytosol of the cell?
1. A.
2. B.
3. C.
4. D.
A. Stage 1: glycolysis
B. Stage 2: oxidation of pyruvate to acetyl CoA
C. Stage 3: Krebs cycle
D: Stage 4: oxidative phosphorylation (chemiosmosis)

Carbon dioxide is released during which stage(s)?
1. Stage 3 only
2. Stages 2 and 3
3. Stages 3 and 4
4. Stages 1, 2, and 3
5. Stages 2, 3, and 4
Which of the following intermediary metabolites enters the Krebs cycle and is formed, in part, by the removal of carbon dioxide from a molecule of pyruvate?
1. lactate
2. glyceraldehyde phosphate
3. oxaloacetic acid
4. acetyl CoA
5. citric acid
When hydrogen ions are pumped from th emitochondrial matrix, across the inner membrane, and into the intermembrane space, the result is
1. the formation of ATP
2. the reduction of NAD+
3. the restoration of the sodium/potassium ion balance across the membrane.
4. the creation of a proton gradient.
5. the lowering of pH in the mitrochondrial matrix.
Carbon skeletons to be croken down during cellular respiration can be obtained from __________.
1. polysaccharides
2. proteins.
3. lipids.
4. Only A and B are correct.
5. A, B, and C are correct
Where is ATP synthase located in the mitochondion?
1. ribosomes
2. cytochrome system
3. outer membrane
4. inner membrane
5. matrix
Each time a molecule of glucose is completely oxidized via aerobic respiration, how many oxygen molecules are consumed?
1. 1
2. 2
3. 6
4. 12
5. None; you consume carbon dioxide molecules instead.
Glycolysis takes place in which location?
1. cytosol
2. matrix
3. intermembrane space
4. cristae
5. outer membrane
Where are the proteins of the electron transport chain located?
1. cytosol
2. matrix
3. intermembrane space
4. cristae
5. outer membrane
Electrons that shuttle across the membrane begin in the ___________.
1. cytosol
2. matrix
3. intermembrane space
4. cristae
5. outer membrane
The electron transport chain energy is used to pump hydrogen ions into which location?
1. cytosol
2. matrix
3. intermembrane space
4. cristae
5. outer membrane
Acetyl CoA accumulates in which location?
1. cytosol
2. matrix
3. intermembrane space
4. cristae
5. outer memberane
In order for a muscel cell to keep working, it must _____________.
1. regenerate ATP at a very fast rate
2. receive sufficient osygen for glycolysis
3. store sufficient ATP as a raw material for oxidative phosphorylation
4. rapidly replace the enzymes of respiration
5. effectively transport NADH into the mitochondria
Cellular respiration harvests the most chemical energy by ______________.
1. substrate-level phosphorylation
2. forming lactate from pyruvate
3. converting oxygen to ATP
4. transferring electrons from organic molecules to oxygen
5. generating carbon dioxide and oxygen in the electron transport chain
During aerobic respiration, electrons travel downhill from
1. food-->Krebs cycle-->ATP-->NAD+
2. food-->NADH-->electron transport chain-->oxygen
3. glucose-->ATP-->oxygen
4. glucose-->ATP-->electron transport chain-->NADH
5. food-->glycolysis-->Krebs cycle-->NADH-->ATP
During aerobic respiration, which of the following directly donates electrons to the electron transport chain at the lowerst energy level?
1. NAD+
2. NADH
3. ATP
4. ADP + Pi
5. FADH2
Inside an active mitochondrion, most electrons follow which pathway?
1. glycolysis-->NADH-->oxidative phosphorylation-->ATP-->oxygen
2. Krebs cycle-->FADH2-->electron transport chain-->ATP
3. electron transport chain-->Krebs cycle-->ATP
4. pyruvate-->Krebs cycle-->ATP-->NADH-->oxygen
5. Krebs cycle-->NADH-->electron transport chain-->oxygen
You eat a cheeseburger and a fresh salad. Which of the following molecules in your food is NOT normally oxidized in aerobic respiration to generate ATP?
1. sucrose
2. lipids
3. nucleic acids
4. proteins
5. amino acids
Which of the following is NOT a food molecule accepted by glycolysis for catabolism?
1. fatty acids
2. sucrose
3. glucose
4. glycerol
5. starch
You have a friend who lost 15 pounds of fat on a diet. Where did the fat go (how was it lost)?
1. It was released as carbon dioxide and water.
2. Chemical energy was converted to heat and then released.
3. It was converted to ATP, which weighs much less than fat.
4. It was broken down to amino acids and eliminated from the body.
5. It was converted to urine and eliminated from the body.
The complete aerobic respiration of sucrose, a disaccharide and fructose, or of maltose (both disaccharides), would release _______ molecules of carbon dioxide.
1. 2
2. 3
3. 6
4. 12
5. None; disaccharides are not food molecules for aerobic respiration.
Folding of the inner membrane forming cristae in mitochondria
1. allows glucose to enter the organelle and fuel the Krebs cycle.
2. increases the production of carbon dioxide, provideing carbon to other reactions.
3. breaks ATP into ADP plus Pi, releasing energy for the Krebs cycle to operate.
4. increases surface area inside the mitochondria, providing space for thousands of copies of the electron transport chain.
5. allows all of the above to occur.