Exam 2 (Chapter 8/9/10)
Refer to Figure , showing the citric acid cycle, as a guide to answer the following questions. Starting with one molecule of isocitrate and ending with fumarate, what is the maximum number of ATP molecules that could be made through substrate-level phosphorylation? 2 1 11 24 12
1
For each molecule of glucose that is metabolized by glycolysis and the citric acid cycle, what is the total number of NADH + FADH2 molecules produced? 5 12 10 4 6
12
How many ATP are generated per acetyl coenzyme A going through the Krebs cycle followed by the electron transport system? 24 12 3 2 36-38
12
Starting with one molecule of glucose, the "net" products of glycolysis are_______? 6 CO2, 6 H2O, 36 ATP, and 2 citrate. 2 NAD+, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O. 2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O. 6 CO2, 6 H2O, 2 ATP, and 2 pyruvate. 2 FADH2, 2 pyruvate, 4 ATP, and 2 H2O.
2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O.
In glycolysis, for each molecule of glucose oxidized to pyruvate 2 molecules of ATP are used and 2 molecules of ATP are produced. 4 molecules of ATP are used and 2 molecules of ATP are produced. 2 molecules of ATP are used and 4 molecules of ATP are produced. 2 molecules of ATP are used and 6 molecules of ATP are produced. 6 molecules of ATP are used and 6 molecules of ATP are produced.
2 molecules of ATP are used and 4 molecules of ATP are produced.
In the presence of oxygen, the process of glycolysis produces which of the following products? 2 lactate 1 lactate 2 glycerol 1 pyruvate 2 pyruvate
2 pyruvate
Photorespiration lowers the efficiency of photosynthesis by preventing the formation of 3-phosphoglycerate molecules RuBP carboxylase molecules. ATP molecules. carbon dioxide molecules. ribulose bisphosphate molecules.
3-phosphoglycerate molecules
Photorespiration lowers the efficiency of photosynthesis by preventing the formation of 3-phosphoglycerate molecules RuBP carboxylase molecules. ATP molecules. carbon dioxide molecules. ribulose bisphosphate molecules.
3-phosphoglycerate molecules
Refer to Figure , showing the citric acid cycle, as a guide to answer the following questions. How many reduced dinucleotides would be produced with four turns of the citric acid cycle? 4 FAD+ and 12 NAD+2 FADH2 and 8 NADH 1 FADH2 and 4 NADH 1 FAD and 4 NAD+ 4 FADH2 and 12 NADH
4 FADH2 and 12 NADH
Approximately how many molecules of ATP are produced from the complete oxidation of two molecules of glucose (C6H12O6) in cellular respiration? 15 38 4 2 76
76
Refer to Figure to answer the following questions. Figure illustrates some of the steps (reactions) of glycolysis in their proper sequence. Each step is lettered. Use these letters to answer the questions. Which step involves an endergonic reaction?
A
Where is ATP synthase located in mitochondria? A)inner membrane b)outer membrane c)cytosol d)mitochondrial matrix e)electron transport chain
A)inner membrane
Heat is classified as______? A. a highly disordered form of energy. B. a highly ordered form of energy. C. the form of energy that fuels life's processes
A. a highly disordered form of energy.
Each ATP molecule contains about 1% of the amount of chemical energy available from the complete oxidation of a single glucose molecule. Cellular respiration produces about 32 ATP from one glucose molecule. What happens to the rest of the energy in glucose? A: It is converted to heat. B:It is released as carbon dioxide and water C: It is stored as fat. D: It is converted to starch. E: It is used to make water from hydrogen ions and oxygen.
A: It is converted to heat.
What are the products of linear photophosphorylation? heat and fluorescence ATP and P700 ADP and NADP ATP and NADPH P700 and P680
ATP and NADPH
Organize the following steps of the light reaction in order. Absorb sunlight, produce high-energy electron carriers, split water, produce oxygen Absorb sunlight, produce oxygen, split water, produce high-energy electron carriers Absorb sunlight, produce high-energy electron carriers, produce oxygen, split water Absorb sunlight, split water, produce oxygen, produce high-energy electron carriers
Absorb sunlight, split water, produce oxygen, produce high-energy electron carriers
Which group includes photosynthetic members? Plants Bacteria Protists All of these
All of these
Refer to Figure to answer the following questions. Figure illustrates some of the steps (reactions) of glycolysis in their proper sequence. Each step is lettered. Use these letters to answer the questions. In which step is an inorganic phosphate added to the reactant?
C
In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (14C) dioxide as a metabolic tracer. The 14C is incorporated first into oxaloacetate. The plant is best characterized as a heterotroph. chemoautotroph. C4 plant. CAM plant. C3 plant.
C4 plant.
What is the chemical equation for glucose? C8H16O8 C6H12O6 C2H4O2 C4H8O4
C6H12O6
Which of the following statements describes the results of this reaction? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy C6H12O6 is reduced and CO2 is oxidized. O2 is reduced and CO2 is oxidized. CO2 is reduced and O2 is oxidized. O2 is oxidized and H2O is reduced. C6H12O6 is oxidized and O2 is reduced.
C6H12O6 is oxidized and O2 is reduced.
Choose the best explanation as to why both consumers and producers perform cellular respiration. A:Both consumers and producers perform cellular respiration to produce the heat necessary to sustain life. B:Both consumers and producers perform cellular respiration to produce the oxygen necessary to sustain life. C:Although they may obtain their sugars in different ways, both consumers and producers rely on cellular respiration to make ATP. D:Both consumers and producers perform cellular respiration to produce the sugars that will be "burned" to fuel the energy of life.
C:Although they may obtain their sugars in different ways, both consumers and producers rely on cellular respiration to make ATP.
Explain how molecules other than glucose can be used as energy sources. A:They are modified first and then enter the same metabolic pathway as glucose. B:Fats, proteins, and other carbohydrates are similar enough to glucose that they utilize the same metabolic pathway without any modifications. C:They have their own unique metabolic pathways. D:They can't; cellular respiration is limited to glucose.
C:They have their own unique metabolic pathways.
In terms of energy production, the Krebs cycle is significant because it A: breaks down glucose. B:directly produces large amounts of ATP. C:reduces the coenzymes NAD and FAD for oxidative phosphorylation. D:provides acetylcoenzyme A for glucose synthesis. E:produces acetylcoenzyme A for fatty acid synthesis.
C:reduces the coenzymes NAD and FAD for oxidative phosphorylation
________ is used to generate 90 percent of the ATP from aerobic glucose catabolism. Chemiosmosis Complex I Complex II
Chemiosmosis
Plastids are storage organelles. A chloroplast is a type of plastid. What does a chloroplast store? Chlorophyll Energy Carbon Electrons
Chlorophyll
________ is a specialized form of anaerobic cellular respiration. Fermentation Chemiosmosis Photosynthesis
Fermentation
Identify the stage (or stages) of cellular respiration that occurs entirely outside of the mitochondria. Citric acid cycle Electron transport chain Glycolysis All of these
Glycolysis
How do we know green light is not absorbed by chlorophyll? Green light does not have enough energy to excite an electron in the photosystem. Green light is the wavelength of light that is reflected instead of absorbed by the chloroplasts. Not enough of the green light penetrates the ozone layer and makes it to the plant. Green light has such a small wavelength that most of it goes straight through the leaves without interacting with the chlorophyll.
Green light is the wavelength of light that is reflected instead of absorbed by the chloroplasts.
Which of the following sequences correctly represents the flow of electrons during photosynthesis? H2O → NADPH → Calvin cycle NADPH → chlorophyll → Calvin cycle NADPH → O2 → CO2 H2O → photosystem I → photosystem II NADPH → electron transport chain → O2
H2O → NADPH → Calvin cycle
Where does cellular respiration occur? In the mitochondria In the chloroplasts In the nucleus In the airways of the respiratory system
In the mitochondria
Phosphofructokinase is an important control enzyme in the regulation of cellular respiration. Which of the following statements describes a function of phosphofructokinase? It is activated by AMP (derived from ADP). It is an allosteric enzyme. It catalyzes the conversion of fructose-1,6-bisphosphate to fructose-6-phosphate, an early step of glycolysis. It is inhibited by citrate, an intermediate of the citric acid cycle. It is activated by ATP.
It is an allosteric enzyme.
Why is glycolysis described as having an investment phase and a payoff phase? It attaches and detaches phosphate groups. It uses stored ATP and then forms a net increase in ATP. It shifts molecules from cytosol to mitochondrion. It uses glucose and generates pyruvate. It both splits molecules and assembles molecules.
It uses stored ATP and then forms a net increase in ATP.
If plant gene alterations cause the plants to be deficient in photorespiration, what would most probably occur? Cells would carry on more photosynthesis. Less ATP would be generated. Cells would carry on the Calvin cycle at a much slower rate. More sugars would be produced. There would be more light-induced damage to the cells.
Less ATP would be generated.
Which of the following is a true distinction between fermentation and cellular respiration? NAD+ functions as an oxidizing agent only in respiration. Only respiration oxidizes glucose. Substrate-level phosphorylation is unique to fermentation. Fermentation, but not respiration, is an example of a catabolic pathway. NADH is oxidized by the electron transport chain in respiration only.
NADH is oxidized by the electron transport chain in respiration only.
Alcohol is a waste product produced by yeast in the presence of sugar and the absence of ________. H2O O2 CO2 ATP
O2
Which of the following statements best describes the relationship between photosynthesis and respiration? Photosynthesis occurs only in plants and respiration occurs only in animals. Photosynthesis stores energy in complex organic molecules, while respiration releases it. ATP molecules are produced in photosynthesis and used up in respiration. Respiration is the reversal of the biochemical pathways of photosynthesis. Respiration is anabolic and photosynthesis is catabolic.
Photosynthesis stores energy in complex organic molecules, while respiration releases it.
Which stage of photosynthesis, if any, can function in the dark? Stage 1 Stage 2 Both Stage 1 and Stage 2 Neither Stage 1 nor Stage 2
Stage 2
Why do some leaves change color (red, yellow, orange, etc.) in the fall? Cold weather denatures the chlorophyll molecule and it begins to reflect different colors. The chlorophyll molecule is modified to absorb different wavelengths of light. Because the leaves are dead. The chlorophyll molecule breaks down and other pigments now become visible.
The chlorophyll molecule breaks down and other pigments now become visible.
Which statement describes the functioning of photosystem II? The excitation is passed along to a molecule of P700 chlorophyll in the photosynthetic unit. Light energy excites electrons in the electron transport chain in a photosynthetic unit. The P680 chlorophyll donates a pair of protons to NADPH, which is thus converted to NADP+. The electron vacancies in P680 are filled by electrons derived from water. The splitting of water yields molecular carbon dioxide as a by-product.
The electron vacancies in P680 are filled by electrons derived from water.
Yeast is used to produce beer and wine but can also make bread rise. All of these processes involve the production of alcohol. Explain why you can eat bread and not get drunk. The amount of alcohol produced is too small to be noticeable. The heat of cooking bakes out the alcohol. The bread-making process produces isopropyl alcohol, not ethyl alcohol. The bread-making process produces ethyl alcohol, not isopropyl alcohol.
The heat of cooking bakes out the alcohol.
When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? The pH of the matrix increases. The electrons gain free energy. ATP synthase pumps protons by active transport. The cytochromes phosphorylate ADP to form ATP. NAD+ is oxidized.
The pH of the matrix increases.
Some bacteria are photosynthetic. Part of the definition of a prokaryote is that they have no membrane-bound organelles, including chloroplasts. Explain how bacteria carry out photosynthesis without chloroplasts. The chlorophyll floats freely in the cell. They still have thylakoids, they just are not compartmentalized into chloroplasts. The entire bacteria cell is a chloroplast with a nucleus. They carry out the steps of photosynthesis in their mitochondria.
They still have thylakoids, they just are not compartmentalized into chloroplasts.
Why are C4 plants able to photosynthesize with no apparent photorespiration? They use PEP carboxylase to initially fix CO2. They are adapted to cold, wet climates. They conserve water more efficiently. They exclude oxygen from their tissues. They do not participate in the Calvin cycle
They use PEP carboxylase to initially fix CO2.
Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate? oxaloacetate acetyl CoA glyceraldehydes-3-phosphate lactate citrate
acetyl CoA
How does pyruvate enter the mitochondrion? diffusion through a pore through a channel facilitated diffusion active transport
active transport
The enzyme alcohol dehydrogenase generates ________ during fermentation. yogurt carbon dioxide alcohol
alcohol
The key enzyme that generates ethanol during fermentation is ________. pyruvate decarboxylase alcohol dehydrogenase lactate dehydrogenase
alcohol dehydrogenase
The two main types of anaerobic cellular respiration are lactic acid fermentation and ________. oxidative fermentation alcohol fermentation beta oxidation ethanal fermentation
alcohol fermentation
In any ecosystem, terrestrial or aquatic, what group(s) is (are) always necessary? autotrophs green plants producers and primary consumers photosynthesizers autotrophs and heterotrophs
autotrophs
Synthesis of ATP by the chemiosmotic mechanism occurs during photosynthesis. neither photosynthesis nor respiration. photorespiration. respiration. both photosynthesis and respiration.
both photosynthesis and respiration.
Glycolysis
breaks down glucose into two molecules of pyruvate
The main purpose of the light-independent reactions is to ________. convert solar energy to chemical energy convert solar energy to ATP for short-term energy use build carbohydrates for long-term energy storage
build carbohydrates for long-term energy storage
Which kind of poison would most likely directly interfere with glycolysis? a. A poison that binds to pyruvate and inactivates it. b. A poison that blocks the passage of electrons along the electron transport chain. c. A poison that closely mimics the structure of glucose but is not metabolized. d. A poison that reacts with oxygen and depletes its concentration in the cell.
c. A poison that closely mimics the structure of glucose but is not metabolized.
What is removed from pyruvate during its conversion into an acetyl group? carboxyl group methyl group hydroxyl group
carboxyl group
Inside an active mitochondrion, most electrons follow which pathway? citric acid cycle → FADH2 → electron transport chain → ATP citric acid cycle → NADH → electron transport chain → oxygen glycolysis → NADH → oxidative phosphorylation → ATP → oxygen pyruvate → citric acid cycle → ATP → NADH → oxygen electron transport chain → citric acid cycle → ATP → oxygen
citric acid cycle → NADH → electron transport chain → oxygen
Krebs Cycle (Citric Acid Cycle)
complete oxidation of glucose to release CO2, produces energy for ETC in the form of 6NADH, 2 FADH2, and 2 ATP (after two turns of cycle)
Which of the following does NOT occur in mitochondria? conversion of pyruvate to lactate Krebs cycle production of carbon dioxide oxidative phosphorylation consumption of oxygen
conversion of pyruvate to lactate
Where does glycolysis takes place? mitochondrial inner membrane mitochondrial intermembrane space cytosol mitochondrial outer membrane mitochondrial matrix
cytosol
Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes? a. glycolysis b. substrate-level phosphorylation c. anabolic pathways d. the citric acid cycle e. oxidative phosphorylation
d. the citric acid cycle
Of the following molecules in the glycolytic pathway (the process of glycolysis), the one with the most chemical energy is _____. a. glyceraldehyde-3-phosphate b. fructose-6-phosphate c. pyruvate d. glucose e. fructose-1,6-bisphosphate
e. fructose-1,6-bisphosphate
The process of ________ utilizes an organic molecule to regenerate NAD+ from NADH. anaerobic cellular respiration fermentation aerobic respiration
fermentation
The final net products of ________ are 2 molecules of ATP and 2 NADH. pyruvate oxidation the citric acid cycle glycolysis
glycolysis
The final net products of ________ are 2 molecules of ATP and 2 NADH. the citric acid cycle pyruvate oxidation glycolysis
glycolysis
Which process in eukaryotic cells will proceed normally whether oxygen (O2) is present or absent? oxidative phosphorylation the citric acid cycle glycolysis chemiosmosis electron transport
glycolysis
ATP is synthesized by substrate-level phosphorylation during which of the following? glycolysis only glycolysis, the Krebs cycle, and during conversion of pyruvate to lactate conversion of pyruvate to lactate only Krebs cycle only glycolysis and the Krebs cycle only
glycolysis and the Krebs cycle only
A molecule that is phosphorylated has been reduced as a result of a redox reaction involving the loss of an inorganic phosphate. has an increased chemical reactivity; it is primed to do cellular work. has less energy than before its phosphorylation and therefore less energy for cellular work. has been oxidized as a result of a redox reaction involving the gain of an inorganic phosphate. has a decreased chemical reactivity; it is less likely to provide energy for cellular work.
has an increased chemical reactivity; it is primed to do cellular work.
What role does O2 play in aerobic respiration? it combines with acetyl-CoA at the start of the Krebs cycle it is given off as a by-product during the oxidation of pyruvate it combines with H2O to help drive the formation of ATP it is the final electron acceptor at the end of the electron transport chain
it is the final electron acceptor at the end of the electron transport chain
The molecule that functions as the reducing agent (electron donor) in a redox or oxidation-reduction reaction neither gains nor loses electrons, but gains or loses energy. loses electrons and gains energy. gains electrons and gains energy. loses electrons and loses energy. gains electrons and loses energy.
loses electrons and loses energy.
Where are the proteins of the electron transport chain located? mitochondrial matrix mitochondrial inner membrane mitochondrial outer membrane mitochondrial intermembrane space cytosol
mitochondrial inner membrane
Where are the proteins of the electron transport chain located? mitochondrial intermembrane space mitochondrial matrix mitochondrial inner membrane cytosol mitochondrial outer membrane
mitochondrial inner membrane
During oxidative phosphorylation, H2O is formed. Where does the oxygen for the synthesis of the water come from? molecular oxygen (O2) pyruvate (C3H3O3-) lactate (C3H5O3-) carbon dioxide (CO2) glucose (C6H12O6)
molecular oxygen (O2)
One function of both alcohol fermentation and lactic acid fermentation is to none of the above reduce FAD+ to FADH2. oxidize NADH to NAD+. reduce NAD+ to NADH. reduce FADH2 to FAD+.
oxidize NADH to NAD+.
What is the final acceptor of electrons in the electron transport? glucose water pyruvate oxygen carbon dioxide
oxygen
Reduction of NADP+ occurs during neither photosynthesis nor respiration. respiration. photorespiration. both photosynthesis and respiration. photosynthesis.
photosynthesis.
Which of the following are directly associated with photosystem I? harvesting of light energy by ATP extraction of hydrogen electrons from the splitting of water P680 reaction-center chlorophyll receiving electrons from plastocyanin passing electrons to plastoquinone
receiving electrons from plastocyanin
When a molecule of NAD+ (nicotinamide adenine dinucleotide) gains a hydrogen atom (not a hydrogen ion) the molecule becomes a reducing agent. oxidized. hydrogenated. reduced. redoxed.
reduced.
In alcohol fermentation, NAD+ is regenerated from NADH during which of the following? reduction of pyruvate to form lactate reduction of acetaldehyde to ethanol (ethyl alcohol) oxidation of pyruvate to acetyl CoA phosphorylation of ADP to form ATP oxidation of NAD+ in the citric acid cycle
reduction of acetaldehyde to ethanol (ethyl alcohol)
Which of the following does not occur during the Calvin cycle? consumption of ATP carbon fixation regeneration of the CO2 acceptor oxidation of NADPH release of oxygen
release of oxygen
Where do the enzymatic reactions of the Calvin cycle take place? thylakoid space thylakoid membranes stroma of the chloroplast outer membrane of the chloroplast electron transport chain
stroma of the chloroplast
The ATP made during fermentation is generated by which of the following? Group of answer choices oxidative phosphorylation aerobic respiration the electron transport chain chemiosmosis substrate-level phosphorylation
substrate-level phosphorylation
The ATP made during glycolysis is generated by oxidation of NADH to NAD+. photophosphorylation. electron transport. chemiosmosis. substrate-level phosphorylation.
substrate-level phosphorylation.
What is the primary function of the Calvin cycle? use NADPH to release carbon dioxide use ATP to release carbon dioxide synthesize simple sugars from carbon dioxide transport RuBP out of the chloroplast split water and release oxygen
synthesize simple sugars from carbon dioxide
Most CO2 from catabolism is released during_________? glycolysis. oxidative phosphorylation. lactate fermentation. the citric acid cycle. electron transport.
the citric acid cycle.
ATP synthase is able to use the potential energy that originates from ________ to produce ATP. Group of answer choices the sodium gradient across the inner mitochondrial membrane complex I complex IV the hydrogen gradient across the inner mitochondrial membrane the phosphorylation of cytochromes
the hydrogen gradient across the inner mitochondrial membrane
Chemiosmosis involves ________. the movement of electrons across a membrane the movement of hydrogen ions across a membrane the movement of hydrogen atoms across a membrane
the movement of hydrogen ions across a membrane
Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be____. to do experiments to generate an action spectrum. to test for liberation of O2 in the light. to test for CO2 fixation in the dark. to determine if they have thylakoids in the chloroplasts. to test for production of either sucrose or starch.
to test for liberation of O2 in the light.
What is the net energy yield for the anaerobic metabolism of one glucose molecule? 36 molecules of ATP and 0 NADH two molecules of ATP and 0 NADH two molecules of ATP and three NADH two molecules of ATP and two NADH two molecules of NADH and 0 ATP PreviousNext
two molecules of ATP and 0 NADH
