chpt 9
A small amount of ATP is made in glycolysis by which of the following processes? (eText Concept 9.1) attachment of a free inorganic phosphate (Pi) group to ADP to make ATP transport of electrons through a series of carriers transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation transfer of electrons and hydrogen atoms to NAD+ harnessing energy from the sun
transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation
In the overall process of glycolysis and cellular respiration, __________ is oxidized and __________ is reduced. (eText Concept 9.1) glucose ... oxygen ATP ... oxygen oxygen ... ATP carbon dioxide ... water glucose ... ATP
glucose...oxygen
Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule? synthesis of acetyl CoA from pyruvate reduction of pyruvate to lactate glycolysis the electron transport chain the citric acid cycle
Glycolysis
In glycolysis in the absence of oxygen, cells need a way to regenerate which compound? (eText Concept 9.5) carbon dioxide lactate glucose ethanol NAD+
NAD+
When a poison such as cyanide blocks the electron transport chain, glycolysis and the citric acid cycle also eventually stop working. Which of the following is the best explanation for this? (eText Concept 9.4) They run out of ADP. Electrons are no longer available from the electron transport chain to power glycolysis and the citric acid cycle. A high level of NADH is present in the cell. NAD+ and FAD are not available for glycolysis and the citric acid cycle to continue. The uptake of oxygen stops because electron transport was inhibited.
NAD+ and FAD are not available for glycolysis and the citric acid cycle to continue
After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of __________. (eText Concept 9.3) NADH FADH2 acetyl CoA CO2 ATP
NADH
In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs? (eText Concept 9.3) Pyruvate is ionized directly to acetyl-coA. Pyruvate is oxidized and a molecule of carbon dioxide is removed. The electrons removed in this process are donated to NADH to produce NAD+. Pyruvate is oxidized and a molecule of carbon dioxide is removed. The electrons removed in this process are used to reduce NAD+ to NADH. Pyruvate is reduced to acetyl-coA, which involves the reduction of pyruvate, the addition of a carbon dioxide from the environment, and its reduction by NADH. Pyruvate is reduced and a molecule of carbon dioxide is removed. The electrons removed in this process are used to oxidize NAD+ to NADH.
Pyruvate is oxidized and a molecule of carbon dioxide is removed. The electrons removed in this process are used to reduce NAD+ to NADH
Which of the following statements is the best explanation of what happens to the temperature and carbon dioxide concentration during a 1-hour class period in a classroom of 300 students if the heating and air conditioning is turned off and all doors are kept closed? (eText Concept 9.1) Neither temperature nor carbon dioxide levels change because cellular respiration is 100% efficient and because carbon dioxide produced by cellular respiration is just as rapidly consumed by cellular respiration. Temperature goes up and the level of carbon dioxide goes down. This is because cellular respiration is an exergonic process that is only about 38% efficient; the remaining energy is lost to the environment as heat. Also, carbon dioxide is being converted to organic molecules such as fats and sugars during cellular respiration. Temperature goes up but carbon dioxide levels remain constant because heat is a by-product of cellular respiration but carbon dioxide is converted to sugar during cellular respiration. Temperature and the level of carbon dioxide rise as heat and carbon dioxide are by-products of cellular respiration. Temperature goes down and carbon dioxide levels remain constant. This is because cellular respiration, being an endergonic reaction, requires an input of heat energy from the environment to occur and because carbon dioxide is neither produced nor consumed by cellular respiration.
Temp. and level of carbon dioxide rise as heat and carbon dioxide are by products of cellular respiration
In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive oxygen. The mice were closely monitored, and after a few minutes radioactive oxygen atoms showed up in __________. (eText Concept 9.3) oxygen gas NADH water carbon dioxide ATP
carbon dioxide
Most CO2 from catabolism is released during electron transport. the citric acid cycle. oxidative phosphorylation. lactate fermentation. glycolysis.
citric acid cycle
Which of the following best describes the electron transport chain? (eText Concept 9.4) Glucose is broken down to a three-carbon compound in preparation for the citric acid cycle. Hydrogen atoms are added to CO2 to make an energy-rich compound. Acetyl CoA is fully oxidized to CO2. Electrons are passed from one carrier to another, releasing a little energy at each step. Electrons are pumped across a membrane by active transport.
electrons are passed from one carrier to another, releasing a little energy at each step
Muscle tissues make lactate from pyruvate to do which of the following? (eText Concept 9.5) produce additional CO2 speed up the rate of glycolysis get rid of pyruvate produced by glycolysis regenerate NAD+ utilize the energy in pyruvate
regenerate NAD+
Why is the citric acid cycle called a "cycle"? (eText Concept 9.3) The acetyl CoA that enters the cycle is regenerated in the last step of the pathway. The four-carbon acid that accepts the acetyl CoA in the first step of the cycle is regenerated by the last step of the cycle. NADH is cycled down the electron transport chain. NAD+ and FAD are recycled. All of the carbon from glucose is cycled back into the atmosphere as carbon dioxide.
the 4 carbon acid that accepts the acetyl CoA in the first step of the cycle is regenerated by the last step
Which of the following substances is/are involved in oxidative phosphorylation? (eText Concept 9.4) oxygen ATP ADP None of the listed responses is correct. The first three listed substances are involved in oxidative phosphorylation.
the first 3 are involved in oxidative phosphorylation
Energy for synthesizing ATP is obtained by ATP synthase directly from which of the following processes? (eText Concept 9.4) the oxidation of glucose the flow of H+ across the inner mitochondrial membrane through the ATP synthase enzyme the reduction of oxygen the oxidation of NADH and FADH2 the movement of electrons through a series of carriers
the flow of H+ across the inner mitochondrial membrane through ATP synthase enzyme
In eukaryotic cells, the components of the electron transport chain are located in or on __________. (eText Concept 9.4) the matrix of the mitochondrion the intermembrane space of the mitochondrion the cytosol the inner membrane of the mitochondrion none of the listed locations
the inner membrane of the mitochondrion
When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs? NAD+ is oxidized. The electrons gain free energy. The cytochromes phosphorylate ADP to form ATP. The pH of the matrix increases. ATP synthase pumps protons by active transport.
the pH of the matrix increases
In the citric acid cycle, for each pyruvate that enters the cycle, one ATP, three NADH, and one FADH2 are produced. For each glucose molecule that enters glycolysis, how many ATP, NADH, and FADH2 are produced in the citric acid cycle? (eText Concept 9.3) about 38 ATP one ATP, three NADH, one FADH2 three ATP, three NADH, one FADH2 two ATP, six NADH, two FADH2 four ATP, six NADH, two FADH2
2 ATPs. 6 NADH, 2FADH2
The overall efficiency of respiration (the percentage of the energy released that is saved in ATP) is approximately __________. (eText Concept 9.4) 0.5% 2% 35% 94% 100%
35%
How many molecules of ATP are gained by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen? (eText Concept 9.3) 2 3 4 about 16 ATP about 32 ATP
4
The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the affinity of oxygen for electrons. H+ concentration across the membrane holding ATP synthase. transfer of phosphate to ADP. oxidation of glucose and other organic compounds. flow of electrons down the electron transport chain.
H+ concentration across the membrane holding ATP synthase
When protein molecules are used as fuel for cellular respiration, __________ are produced as waste. (eText Concept 9.6) molecules of lactate sugar molecules amino groups ethanol and CO2 fatty acids
amino groups
During aerobic respiration, molecular oxygen (O2) is used for which of the following purposes? (eText Concept 9.4) between glycolysis and the citric acid cycle to split a carbon from pyruvate, producing CO2 as a source of O2 in every reaction that produces CO2 at the end of the electron transport chain to accept electrons and form H2O at the end of the citric acid cycle to regenerate citric acid at the end of glycolysis to oxidize pyruvate
at the end of the electron transport chain to accept electrons and form H2O
Which of the following is the process in which glucose is oxidized to generate two molecules of pyruvate, and in which ATP and NADH are produced? (eText Concept 9.1) the citric acid cycle chemiosmosis the oxidation of pyruvate fermentation None of the listed responses is correct.
none
Which of the following processes generates most of the NADH that delivers electrons to the electron transport chain? (eText Concept 9.3) anabolic pathways glycolysis the citric acid cycle oxidative phosphorylation substrate-level phosphorylation End of Question 15
citric acid cycle
Where do the reactions of glycolysis occur in a eukaryotic cell? (eText Concept 9.1) across the inner membrane of the mitochondrion the inner membrane of the mitochondrion the cytosol the matrix of the mitochondrion in the intermembrane space of the mitochondrion
cytosol
Fermentation is essentially glycolysis plus an extra step in which pyruvate is reduced to form lactate or alcohol and carbon dioxide. This last step __________. (eText Concept 9.5) extracts a bit more energy from glucose enables the cell to recycle the reduced NADH to oxidized NAD+ enables the cell to make pyruvate into substances it can use removes poisonous oxygen from the environment prevents pyruvate from accumulating
enable the cell to recycle the reduced NADH to oxidize NAD+
The function of cellular respiration is to __________. (eText Concept 9.1) synthesize macromolecules from monomers extract CO2 from the atmosphere produce carbohydrates extract usable energy from glucose reduce CO2
extract usable energy from glucose
A gram of fat oxidized by respiration produces approximately twice as much ATP as a gram of carbohydrate. Which of the following best explains this observation? (eText Concept 9.6) Fats do not form true macromolecules as sugars do. Fats are less soluble in water than sugars. Fats are closely related to lipid molecules, which are the basic building blocks of cellular membranes. Fats are better electron donors to oxygen than are sugars. Fats are produced when cells take in more food than they need.
fats are better electron donors to oxygen than sugars
Most of the electrons removed from glucose by cellular respiration are used for which of the following processes? (eText Concept 9.4) reducing NAD+ to NADH in glycolysis and the citric acid cycle producing a proton gradient for ATP synthesis in the mitochondria driving substrate-level phosphorylation in glycolysis The first two choices are correct. The second and third answers are correct.
first 2 choices are correct
If muscle cells in the human body consume O2 faster than it can be supplied, which of the following is likely to result? (eText Concept 9.5) The muscle cells will have more trouble making enough ATP to meet their energy requirements. The cells will not be able to carry out oxidative phosphorylation. The cells will consume glucose at an increased rate. Only the first two answers are correct. The first three answers are correct.
first 3
If significant amounts of materials are removed from the citric acid cycle to produce amino acids for protein synthesis, which of the following will result? (eText Concept 9.6) Less ATP will be produced by the cell. Less CO2 will be produced by the cell. The four-carbon compound that combines with acetyl CoA will have to be made by some other process. The first two answers are correct. The first three answers are correct.
first 3
Which of the following represents the major (but not the only) energy accomplishment of the citric acid cycle? (eText Concept 9.3) formation of NADH and FADH2 utilization of O2 formation of ATP formation of CO2 completion of substrate-level phosphorylation
formation of NADH and FADH2
Which of the following molecules in the process of glycolysis possesses the most chemical energy? (eText Concept 9.2) glyceraldehyde-3-phosphate fructose-1,6-bisphosphate fructose-6-phosphate glucose pyruvate
fructose - 1,6- bisphosphate
Of the metabolic pathways listed below, which is the only pathway found in all organisms? (eText Concept 9.5) the electron transport chain cellular respiration fermentation glycolysis the citric acid cycle End of Question 44
glycolysis
A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to kill bacteria in people with infections. However, he cannot do this because __________. (eText Concept 9.2) glycolysis produces so little ATP that the drug will have little effect bacteria are prokaryotes; they usually do not need to perform glycolysis human cells must also perform glycolysis; the drug might also poison them glycolysis can occur without the action of enzymes this step in the pathway of glycolysis can be skipped in bacteria, but not in humans
human cells must perform glycolysis; the drug might also poison them
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? (eText Concept 9.4) It is used to make water from hydrogen ions and oxygen. It is released as carbon dioxide and water It is stored as fat. It is converted to heat. It is converted to starch.
it is converted to heat
If a compound that allows protons to freely diffuse across membranes is added to cells that are actively metabolizing glucose via cellular respiration, which of the following processes would stop? (eText Concept 9.4) glycolysis electron transport ATP synthesis All of the listed responses are correct. None of the listed responses is correct.
none
When solid tumors of animals reach a certain size, the center of the tumor begins to die. To prevent this, the tumor can recruit new blood vessels. What purpose does the recruitment of blood vessels to growing tumors serve? (eText Concept 9.4) It supplies a non-oxygen electron acceptor to cells so that the cells can respire anaerobically. It supplies glucose to the rapidly dividing cells of the tumor. It supplies oxygen so that aerobic cellular respiration can occur instead of fermentation. It supplies a non-oxygen electron acceptor to cells so that the cells can respire anaerobically, and it supplies oxygen so that aerobic cellular respiration can occur instead of fermentation. It supplies oxygen so that aerobic cellular respiration can occur instead of fermentation, and it supplies glucose to the rapidly dividing cells of the tumor.
it supplies oxygen so that aerobic cellular respiration can occur instead of fermentation, and it supplies glucose to the rapidly dividing cells of the tumor
Sports physiologists at an Olympic training center wanted to monitor athletes to determine at what point their muscles were functioning anaerobically. They could do this by checking for a buildup of which of the following compounds? (eText Concept 9.5) lactate oxygen carbon dioxide ATP ADP
lactate
A molecule becomes more oxidized when it __________. (eText Concept 9.1) changes shape gains an electron loses a hydrogen (H+) ion loses an electron gains a hydrogen (H+) ion
loses an electron
Where do the reactions of the citric acid cycle occur in eukaryotic cells? (eText Concept 9.3) across the inner membrane of the mitochondrion the cytosol the cristae of the mitochondrion the intermembrane space of the mitochondrion the matrix of the mitochondrion
matrix of mitochondria
Which of the following is the source of the energy that produces the chemiosmotic gradient in mitochondria? (eText Concept 9.4) ATP the production of NADH the components of the electron transport chain movement of electrons down the electron transport chain an ATP-dependent proton pump
movement of electrons down the electron transport chain
Which of the following is a correct description of the events of cellular respiration in proper sequence? (eText Concept 9.1) oxidation of glucose to pyruvate; oxidation of pyruvate; citric acid cycle; oxidative phosphorylation glycolysis; reduction of pyruvate; citric acid cycle; oxidative phosphorylation oxidation of glucose to pyruvate; reduction of pyruvate; citric acid cycle; oxidative phosphorylation oxidation of pyruvate; citric acid cycle; oxidation of glucose to pyruvate; oxidative phosphorylation glycolysis; oxidative phosphorylation; citric acid cycle; oxidation of pyruvate
oxidation of glucose to pyruvate, oxidation of pyruvate, citric acid cycle, oxidative phosphorylation
Most of the ATP produced in cellular respiration comes from which of the following processes? (eText Concept 9.1) oxidative phosphorylation substrate-level phosphorylation the citric acid cycle glycolysis reduction of NADH
oxidative phosphorylation
During the reaction C6H12O6 + 6 O2 → 6 CO2 + 6 H2O, which compound is reduced as a result of the reaction? (eText Concept 9.1) oxygen water carbon dioxide glucose both glucose and carbon dioxide
oxygen
The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is oxygen. pyruvate. NAD+. water. ADP.
oxygen
Oxygen gas (O2) is one of the strongest oxidizing agents known. The explanation for this is that __________. (eText Concept 9.1) the oxygen atom is very electronegative oxygen gas contains a double bond oxygen acts as the final electron acceptor in cellular respiration oxygen gas is composed of two atoms of oxygen oxygen is so abundant in the atmosphere
oxygen is very electronegative
In mitochondria, exergonic redox reactions are the source of energy driving prokaryotic ATP synthesis. provide the energy that establishes the proton gradient. are coupled via phosphorylated intermediates to ender-gonic processes. are directly coupled to substrate-level phosphorylation. reduce carbon atoms to carbon dioxide.
provide the energy that establishes the proton gradient
The energy given up by electrons as they move through the electron transport chain is used in which of the following processes? (eText Concept 9.4) the breakdown of glucose the production of CO2 the production of NADH and FADH2 pumping H+ across a membrane the oxidation of water
pumping H+ across a membrane
What is the oxidizing agent in the following reaction? Pyruvate + NADH + H+ S Lactate + NAD+ oxygen pyruvate NADH NAD+ lactate
pyruvate
Which of the following events accompanies the conversion of pyruvate to acetyl CoA before the citric acid cycle? (eText Concept 9.3) release of CO2 and synthesis of NADH removal of coenzyme A formation of CO2 and synthesis of ATP regeneration of NAD+ release of CO2 and release of coenzyme A
regeneration of NAD+
There is no production of carbon dioxide in glycolysis. Which of the following is the best explanation for this fact? (eText Concept 9.2) There are no oxidation or reduction reactions in glycolysis to produce CO2. The initial steps of glycolysis require an input of energy in the form of ATP (two per glucose). Glucose contains more carbons than the number of carbons found in the pyruvate products that are produced by glycolysis. The products of glycolysis contain the same total number of carbon atoms as in the starting material. There is very little ATP produced in glycolysis.
the products of glycolysis contain the same total number of carbon atoms as in the starting material
In brewing beer, maltose (a disaccharide of glucose) is __________. (eText Concept 9.5) a sweetener the substrate for alcoholic fermentation a substitute for pyruvate that cannot be made in yeast one of the enzymes for alcoholic fermentation the substrate for aerobic respiration
the substrate for alcoholic fermentation