Chapter 06: How Cells Harvest Chemical Energy Dynamic Study Module
Glycolysis is a series of reactions that can be divided into two phases: an "energy investment" and an "energy payoff" phase. Which of the following is produced at the end of the "energy investment" phase in the metabolism of one molecule of glucose? -2 molecules of glyceraldehyde-3-phosphate (G3P), a 3-carbon sugar -1 molecule of glyceraldehyde-3-phosphate (G3P), a 3-carbon sugar -2 molecules of ATP -4 molecules of ATP -2 molecules of pyruvate
2 molecules of glyceraldehyde-3-phosphate (G3P), a 3-carbon sugar
How many molecules of ATP are produced in (1) glycolysis, (2) the citric acid cycle, and (3) oxidative phosphorylation for a single glucose molecule? -2; 2; 28 -4; 2; 32 -2; 1; 32 -1; 4; 32 -2; 4; 28
2; 2; 28
Each turn of the citric acid cycle yields which of the following molecules that will go on to donate their electrons to the electron transport chain? -3 molecules of NADH and 1 molecule of FADH2 -2 molecules of NADH and 3 molecules of FADH2 -3 molecules of NAD+ and 1 molecule of FAD -3 molecules of NADH and 1 molecule of NAD+ -3 molecules of NADH and 2 molecules of ATP
3 molecules of NADH and 1 molecule of FADH2
An hour of walking at 3 mph consumes approximately __________ times as much energy as an hour of sitting and writing. -8 -5 -2 -15 -They consume about the same amount of energy.
8
What benefits do scientists think might result from increasing the amount of brown fat in people who are obese or who have type 2 diabetes? -Such people might benefit from a higher proportion of brown to white fat, which would reduce the amount of stored fat. -Brown fat stores more calories than white fat and does not "bulk up" the way white fat does, so people's appearances would improve. -Because brown fat is more efficient metabolically at making ATP, it could be a good alternate source of fuel for such people. -Brown fat weighs less than white fat, so increasing its amount would be equivalent to losing weight. -Brown fat is added during exercise, so it would be a good indicator of people's exercise levels.
Such people might benefit from a higher proportion of brown to white fat, which would reduce the amount of stored fat.
Which of the following events takes place in the cell's cytosol? -the formation of ATP by substrate phosphorylation -the attachment of oxidized pyruvate to acetyl CoA -the formation of ATP by chemiosmosis -oxidative phosphorylation -the generation of FADH2
the formation of ATP by substrate phosphorylation
Which of the following statements about brown fat is/are correct? (Select all that apply) -Brown fat produces more heat and more ATP than white fat. -Brown fat uses glucose and is metabolically very active. -Brown fat metabolism is stimulated by exposure to cold. -Brown fat helps keep infants warm.
-Brown fat uses glucose and is metabolically very active. -Brown fat metabolism is stimulated by exposure to cold. -Brown fat helps keep infants warm.
(Match the following terms to the description of the processes involved.) -breaks down organic molecules to produce ATP and consumes oxygen -breaks down organic molecules to produce ATP without consuming oxygen -produces oganic molecules and releases oxygen
-cellular respiration -fermentation -photosynthesis
Oxidation-reduction reactions involve the transfer of electrons from one molecule to another. Match the terms to the correct process. -often represents the movement of an electron -addition of electrons to a substance -loss of electrons from a substance
-hydrogen atom -reduction -oxidation
(Match the following locations in a mitochondrion with the correct processes/description.) -High concentration of H+ ions here will drive chemiosmosis. -Oxygen accepts two electrons and picks up two hydrogen ions (H+), forming water. -Electrons are passed from carrier to carrier.
-intermembrane space -mitochondrial matrix -inner mitochondrial membrane
In addition to providing fuel in the form of ATP, the intermediates of cellular respiration also provide __________. (Select all that apply) -the building blocks of proteins -the building blocks of fats -the substrate for anaerobic fermentation reactions -oxygen to support life on Earth
-the building blocks of proteins -the building blocks of fats
Which of the following statements comparing lactic acid fermentation and alcohol fermentation is inaccurate? -Both reduce pyruvate to lactate. -Both regenerate NAD+. -Both use glycolysis. -Both are anaerobic. -Both are conducted by microorganisms.
Both reduce pyruvate to lactate.
Which of the following is the summary equation for cellular respiration? -C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP + heat -2C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP + heat -C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP -6CO2+ 6H2O + energy→ C6H122O6+ 6O2 -6CO2+ 6H2O + energy→ 2C6H122O6+ 6O2
C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP + heat
The bubbles in dough that arise after yeast has been added are __________. -CO2, a product of alcohol fermentation -CO2, a product of lactic acid fermentation -O2, a product of alcohol fermentation -O2, a product of lactic acid fermentation -ethanol, a product of alcohol fermentation
CO2, a product of alcohol fermentation
__________ generates the ATP created in fermentation reactions. -Glycolysis -The citric acid cycle -Oxidative phosphorylation -Chemiosmosis -Ethanol
Glycolysis
What is the role of oxygen in the electron transport chain? -Its high electronegativity makes it the final electron acceptor. -Its high electronegativity makes it the primary electron donor. -When it combines with hydrogen, water is formed. -Its low electronegativity makes it the final electron acceptor. -It can either accept or donate electrons in response to feedback mechanisms.
Its high electronegativity makes it the final electron acceptor.
Which of the following statements about NADH and NAD+ is correct? -NADH delivers electrons to the electron transport chain in oxidative phosphorylation and becomes oxidized to NAD+. -NADH delivers electrons to the electron transport chain in oxidative phosphorylation and becomes reduced to NAD+. -NAD+ delivers electrons to the electron transport chain in oxidative phosphorylation and becomes oxidized to NADH. -NAD+ delivers electrons to the electron transport chain in oxidative phosphorylation and becomes reduced to NADH. -NAD+ delivers electrons to the electron transport chain in glycolysis and becomes oxidized to NADH.
NADH delivers electrons to the electron transport chain in oxidative phosphorylation and becomes oxidized to NAD+.
Several genetic disorders of mitochondria have now been identified. If such a defect resulted in a less active electron transport chain, what would you predict might occur? (Note: think of this in terms of basic mechanisms; genetic disorders rarely affect just one process.) -The concentration of ADP within the mitochondrial matrix would increase. -The concentration of ADP within the mitochondrial matrix would decrease. -The concentration of ATP within the mitochondrial matrix would increase. -The concentration of H+ ions within the intermembrane space would increase. -The number of electron carriers in the inner mitochondrial matrix would decrease.
The concentration of ADP within the mitochondrial matrix would increase.
Which of the following is a correct statement about the relationship between photosynthesis and cellular respiration? -The products of photosynthesis are the reactants of cellular respiration, and the products of cellular respiration are the reactants of photosynthesis. -The reactants of photosynthesis and of cellular respiration are the same, but the products of the two reactions are different. -Both reactions use the same reactants, but in different proportions. -Without sunlight, neither photosynthesis nor cellular respiration can occur. -Photosynthesis and cellular respiration evolved in parallel, with approximately the same time course.
The products of photosynthesis are the reactants of cellular respiration, and the products of cellular respiration are the reactants of photosynthesis.
Why do fats make such excellent cellular fuel? -They contain many hydrogen atoms. -They contain many oxygen atoms. -Glycerol is an intermediate in glycolysis. -They contain many calories. -They contain essential vitamins.
They contain many hydrogen atoms.
Which of the following processes must be present before ATP can be generated in oxidative phosphorylation? -a higher concentration of H+ within the mitochondrial intermembrane space than within the mitochondrial matrix -a higher concentration of ATP synthase within the mitochondrial intermembrane space than within the mitochondrial matrix -a lower concentration of H+ within the mitochondrial intermembrane space than within the mitochondrial matrix -the presence of four electron carrier complexes within the mitochondrial matrix -the presence of four electron carrier complexes within the cytosol
a higher concentration of H+ within the mitochondrial intermembrane space than within the mitochondrial matrix
Walking at 3 mph burns about 245 kcal/hour. A slice of pizza contains about 474 kcal. How far would you have to walk to burn off the calories in that slice of pizza? -about 6 miles -about 3 miles -about 2 hours -about 1 mile -Insufficient information is provided to calculate an answer.
about 6 miles
At which stage of cellular respiration is the first molecule of CO2 released? -during the oxidation of pyruvate to acetyl CoA -during the synthesis of pyruvate -during the citric acid cycle -during glycolysis -during oxidative phosphorylation
during the oxidation of pyruvate to acetyl CoA
Which out of the listed choices is the earliest metabolic pathway to have developed in living things? -glycolysis -cellular respiration -citric acid cycle -electron transport chain -conversion of pyruvate to acetyl CoA
glycolysis
What is the correct order of the stages of cellular respiration? -glycolysis, citric acid cycle, oxidative phosphorylation -citric acid cycle, glycolysis, oxidative phosphorylation -glycolysis, oxidative phosphorylation, citric acid cycle -oxidative phosphorylation, glycolysis, citric acid cycle -oxidative phosphorylation, citric acid cycle, glycolysis
glycolysis, citric acid cycle, oxidative phosphorylation
The 2-carbon compound that enters the citric acid cycle joins with which of the following molecules before it begins its turn around the cycle? -oxaloacetate, a 4-carbon molecule -oxaloacetate, a 6-carbon molecule -pyruvate, a 4-carbon molecule -G3P, a 4-carbon molecule -glucose, a 6-carbon molecule
oxaloacetate, a 4-carbon molecule
Which of the following is the best description of substrate-level phosphorylation in glycolysis? -the transfer of a phosphate group from a substrate molecule to ADP -the transfer of a phosphate group from a substrate molecule to AMP -the generation of ATP by ATP synthase -the transfer of a phosphate group from ATP to a substrate molecule -the transfer of a phosphate group from NAD+ to NADH
the transfer of a phosphate group from a substrate molecule to ADP