AP Bio Test 3
Which of the following correctly uses the data to justify the claim that the phosphagen system is an immediate, short-term source of ATP for muscle cells? A ATP production by the phosphagen system increases and decreases rapidly following the start of the exercise period. B ATP production by the phosphagen system increases gradually and continuously throughout the entire exercise period. C The ATP produced by the phosphagen system contains more energy per molecule than does the ATP produced by the other pathways. D ATP hydrolysis in muscle cells occurs immediately after the start of the exercise period but stops before the end of the exercise period.
ATP production by the phosphagen system increases and decreases rapidly following the start of the exercise period.
Which of the following observations best helps justify the researcher's claim? A Light-capturing pigment molecules in green plants absorb red, blue, and violet light but reflect green light. B The energy of a photon of light is proportional to its frequency and inversely proportional to its wavelength. C As light energy is converted to chemical energy by metabolic processes, some of the energy is lost as heat. D Captured energy is stored in the molecular bonds of organic molecules, including simple sugars and starch.
As light energy is converted to chemical energy by metabolic processes, some of the energy is lost as heat.
Which of the following statements best supports the researcher's claim? A Atmospheric carbon dioxide is produced by the burning of fossil fuels, which are formed from the remains of living organisms such as plants. B Atmospheric carbon dioxide is a byproduct of cellular respiration, which is a metabolic process that occurs in plants and other living organisms. C Atmospheric carbon dioxide typically enters plant leaves through stomata, which plants rely on for regulating gas exchange with the atmosphere. D Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds.
Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds.
An increase in the rate of oxygen production by algae would be accompanied by a comparable increase in the rate of production of which of the following substances? A C6H12O6 B CO2 C CH4 D NH3 E H2O
C6H12O6
Which of the following is the best explanation for the pattern of change in mass of the organisms over time? A Water loss due to evaporation B Cellular respiration C The law of conservation of matter D Growth and reproduction
Cellular respiration
Which of the following statements best predicts the effect of increasing the concentration of substrate (ethyl alcohol), while keeping the concentration of the inhibitor (methyl alcohol) constant? A There will be an increase in formaldehyde because ADH activity increases. B Competitive inhibition will be terminated because ethyl alcohol will bind to methyl alcohol and decrease ADH activity. C The peptide bonds in the active site of the enzyme will be denatured, inhibiting the enzyme. D Competitive inhibition will decrease because the proportion of the active sites occupied by substrate will increase.
Competitive inhibition will decrease because the proportion of the active sites occupied by substrate will increase.
Which of the following statements best helps explain the reaction specificity of hexokinase? A Both glucose and water are polar molecules that form favorable interactions with charged and polar amino acid side chains in hexokinase's active site. B Both glucose and water have oxygen atoms that can form covalent bonds with the phosphorus atoms of phosphate groups. C Glucose is an energy-rich organic molecule that can be broken down by glycolysis to produce ATP, whereas water is an inorganic molecule. D Glucose has the right shape and charge to cause hexokinase to undergo a structural change needed for catalysis, whereas water does not.
Glucose has the right shape and charge to cause hexokinase to undergo a structural change needed for catalysis, whereas water does not.
Which of the following questions is most relevant to understanding the Calvin cycle? A How does chlorophyll capture light? B How is ATP used in the formation of 3-carbon carbohydrates? C How is NADP+ reduced to NADPH? D How is ATP produced in chemiosmosis?
How is ATP used in the formation of 3-carbon carbohydrates?
Hereditary hemochromatosis (HHC) is an iron storage disease that results in reduced uptake of iron into cells. Based on the data, which of the following is the most likely effect of HHC on ferritin protein levels? A Elevated levels of ferritin protein because there is more iron in the blood of affected individuals B Reduced levels of ferritin protein because there is less iron in the cytosol of affected individuals C Elevated levels of ferritin protein because ferritin replaces the mutant protein in affected individuals D Reduced levels of ferritin protein because iron stimulates ferritin breakdown
Reduced levels of ferritin protein because there is less iron in the cytosol of affected individuals
Which of the following actions will provide the most appropriate negative control for the experiment? A Repeating the experiment with a fourth enzyme B Repeating the experiment at several different temperatures C Repeating the experiment with denatured enzymes D Repeating the experiment using several different methods for measuring pH
Repeating the experiment with denatured enzymes
Additional observations were made on day 21, and no yellow-leaved seedlings were found alive in either dish. This is most likely because A yellow-leaved seedlings were unable to absorb water from the paper towels B taller green-leaved seedlings blocked the light and prevented photosynthesis C yellow-leaved seedlings were unable to convert light energy to chemical energy D a higher rate of respiration in yellow-leaved seedlings depleted their stored nutrients
yellow-leaved seedlings were unable to convert light energy to chemical energy
The rate of oxygen consumption in germinating pea seeds at 26ºC is A 0.05 mL / min B 0.25 mL / min C 0.50 mL / min D 0.75 mL / min E 1.00 mL / min
0.05 mL / min
The maximum production rate of acetyl-CoA under condition 1 is closest to which of the following? A 1 micromole/sec B 24 micromoles/sec C 35 micromoles/sec D 65 micromoles/sec
1 micromole/secmicromole/sec
Which of the following radiolabeled precursors is most appropriate for the researcher to use? A 15N-labeled N2, because atmospheric nitrogen is fixed to amino acids by photosynthesis B 14C-labeled CO2, because atmospheric carbon is fixed to carbohydrates by photosynthesis C 35S-labeled methionine, because amino acids are incorporated into lipids during photosynthesis D 32P-labeled phosphate, because lipids are stored in plants as phospholipids
14C-labeled CO2, because atmospheric carbon is fixed to carbohydrates by photosynthesis
Based on Figure 1, the net number of ATP molecules produced during glycolysis from the metabolism of a single glucose molecule is closest to which of the following? A 0 B 2 C 4 D 8
2
If NaF is added to cells undergoing cellular respiration, which of the following will most likely accumulate in the cells? A Glucose Transporter B Pyruvate C Phosphoenolpyruvate (PEP) D 2-phosphoglycerate
2-phosphoglycerate
Based on the data in Table 1, which of the following is the earliest time point at which there is a statistical difference in average pH between the control and treatment groups? A 5 minutes B 15 minutes C 20 minutes D 35 minutes
35 minutes
Based on the data in Figure 1, the concentration of iron in the control diet used in the investigation is most likely within which of the following ranges? A 20-25 mg/kg B 35-40 mg/kg C 70-75 mg/kg D 100-125 mg/kg
35-40 mg/kg
During which time interval is the reaction rate lowest? A 0-1 minute B 1-2 minutes C 2-3 minutes D 3-4 minutes E 4-5 minutes
4-5 minutes
The energy required to run the Calvin cycle reactions of photosynthesis comes from which two substances produced during the light-dependent reactions? A ATP and NADPH B ADP and PO4 C H+ and PO2 D O2 and CO2 E H2O and CO2
ATP and NADPH
Which of the following statements best helps justify the researcher's claim? A ADP is a small molecule that some cells release into their environment as a way of communicating with other cells. B ATP hydrolysis is an energy-releasing reaction that is often coupled with reactions that require an input of energy. C Inorganic phosphate (Pi) is a substance that cells typically acquire from their environment. D ATP synthase is a mitochondrial enzyme that catalyzes the conversion of ADP and Pi to ATP.
ATP hydrolysis is an energy-releasing reaction that is often coupled with reactions that require an input of energy.
The results of the experiment can be used as evidence in support of which of the following scientific claims about mitochondrial activity? A Mitochondria in a cell-free environment are unable to convert thermal energy into ATP. B The electron transport chain pumps electrons from the cytosol to the mitochondrial matrix. C ATP production in mitochondria requires a hydrogen ion gradient that favors movement of protons into the mitochondrial matrix. D ATP synthase molecules change their orientation in relation to the proton gradient across the mitochondrial membrane.
ATP production in mitochondria requires a hydrogen ion gradient that favors movement of protons into the mitochondrial matrix.
Which of the following statements about the rate of CO2 fixation in the two types of plants is supported by the data shown in the figures? A At 21% O2, plant type 2 has a lower rate of CO2 fixation than plant type 1 does in both types of soil. B At 1% O2, plant type 2 has a higher rate of CO2 fixation than plant type 1 does in the dry soil but not in the control soil. C Plant types 1 and 2 have a statistically different rate of CO2 fixation in both soil types at both oxygen levels. D The rate of CO2 fixation is the same in both types of plants in the control soil at both oxygen levels.
At 21% O2 , plant type 2 has a lower rate of CO2 fixation than plant type 1 does in both types of soil.
The figures can best assist in answering which of the following questions? A Do electron transport chains create a gradient so that ATP synthase can generate ATP molecules? B What are the sources of energy that drive mitochondrial and chloroplast electron transport systems? C What is the optimal temperature at which ATP synthase chemically converts ADP and a phosphate group into one molecule of ATP? D What is the evolutionary relationship between the ATP synthase in mitochondria and the ATP synthase in chloroplasts?
Do electron transport chains create a gradient so that ATP synthase can generate ATP molecules?
Which of the following questions can best be answered by the diagram? A Does the addition of an enzyme reduce the activation energy required for a reaction? B Does the addition of an enzyme result in the formation of covalent bonds? C Does the addition of an enzyme produce a greater amount of products? D Does the addition of an enzyme change the pathway for the reaction?
Does the addition of an enzyme reduce the activation energy required for a reaction?
Which of the following questions would provide the best direction for a researcher who wanted to study the impact of abnormally high blood-sugar levels on cellular homeostasis in diabetics? A Are cells in diabetics larger in size than those in nondiabetics? B Do the cells in diabetics have more potassium ion channels in the cell membrane than the cells in nondiabetics do? C Does water move from cells into blood vessels more rapidly in diabetics than in nondiabetics when blood-sugar levels are higher than normal? D Do the cells of diabetics use simple sugars as an energy source?
Does water move from cells into blood vessels more rapidly in diabetics than in nondiabetics when blood-sugar levels are higher than normal?
If the input water is labeled with a radioactive isotope of oxygen, 18O, then the oxygen gas released as the reaction proceeds is also labeled with 18O. Which of the following is the most likely explanation? A During the light reactions of photosynthesis, water is split, the hydrogen atoms combine with the CO2, and oxygen gas is released. B During the light reactions of photosynthesis, water is split, removing electrons and protons, and oxygen gas is released. C During the Calvin cycle, water is split, regenerating NADPH from NADP+, and oxygen gas is released. D During the Calvin cycle, water is split, the hydrogen atoms are added to intermediates of sugar synthesis, and oxygen gas is released.
During the light reactions of photosynthesis, water is split, removing electrons and protons, and oxygen gas is released.
Which of the following best explains the connection between energy, growth, and the maintenance of an ordered system in the experiment? A Energy input from light is required for the grass to grow and maintain an ordered structure. B The grass obtains the energy for growth and maintenance of order from nutrients from the soil. C The grass couples the release of energy from the light reactions with the production of oxygen (O2) used to produce sugars for growth. D Energy is required for the growth of the grass but not the maintenance of order.
Energy input from light is required for the grass to grow and maintain an ordered structure.
PFK can be allosterically inhibited by ATP at high concentrations. Which of the following is the benefit of regulating glycolysis by the concentration of ATP? A Glycolysis proceeds when the intracellular concentration of ATP is low, which provides ATP to drive cellular reactions. B Glycolysis proceeds when the intracellular concentration of ATP is high and the cell stores ATP for future use. C Glycolysis is inhibited when the intracellular concentration of ATP is low because PFK requires ATP as a substrate for the reaction it catalyzes. D Glycolysis is inhibited when the intracellular concentration of ATP is high because ATP will compete with fructose 1,6-bisphosphate for binding to the active site on the enzyme.
Glycolysis proceeds when the intracellular concentration of ATP is low, which provides ATP to drive cellular reactions.
Enzymes with their highest activity at an alkaline (basic) pH are represented by which of the following graphs? A I only B II only C III only D I and III only E I and IV only
II only
Which of the following provides the best reasoning to justify the researcher's claim? A In green light, more chlorophyll a molecules are produced, reflecting more light to other cyanobacteria to be used for photosynthesis. B In green light, more phycoerythrin molecules are produced, allowing more green light to be absorbed, thus increasing photosynthesis. C In green light, cyanobacteria that have more phycocyanin molecules are less likely to survive and reproduce. D In green light, cyanobacteria that have more allophycocyanin molecules are more likely to survive and reproduce.
In green light, more phycoerythrin molecules are produced, allowing more green light to be absorbed, thus increasing photosynthesis.
Which of the following questions will best direct an investigation of the mechanism of ATP synthase? A What is the source of the inorganic phosphate that is used to generate ATP from ADP? B Is the phosphorylation of ADP by ATP synthase dependent on the formation of a proton gradient? C Can ATP synthase use the energy released by phosphorylation of ADP to pump protons against a concentration gradient? D Can oxidative phosphorylation be uncoupled from the electron transport chain?
Is the phosphorylation of ADP by ATP synthase dependent on the formation of a proton gradient?
Which of the following best justifies the use of tube 2 as a control treatment? A It was a negative control for the accuracy of the spectrophotometer, ensuring that an accurate reading for treatment cuvette 2 would be made. B It was a negative control for the chemical stability of the chlorophyll suspension, ensuring that changes in absorbance could only be attributed to changes in chlorophyll content. C It was a positive control for the change in DCPIP color associated with changes in light intensity. D It was a positive control for measuring the effect of DCMU on the reaction.
It was a positive control for measuring the effect of DCMUDCMU on the reaction
Which of the following statements best justifies the inclusion of test tube V as a control in the experiment? A It will provide a measurement of amylase activity at an acidic pH. B It will provide a measurement of amylase activity at a basic pH. C It will show the color change that occurs in the absence of enzyme activity. D It will show the color change that occurs in the absence of the amylase protein.
It will show the color change that occurs in the absence of enzyme activity.
Based on the data in Figure 1, which of the following most likely represents the change in energy that occurs when ATP hydrolysis is coupled with the phosphorylation of a substrate? A Line 4 represents ATP hydrolysis, and line 1 represents phosphorylation of a substrate. B Line 1 represents ATP hydrolysis, and line 4 represents phosphorylation of a substrate. C Line 2 represents ATP hydrolysis, and line 3 represents phosphorylation of a substrate. D Line 3 represents ATP hydrolysis, and line 2 represents phosphorylation of a substrate.
Line 1 represents ATP hydrolysis, and line 4 represents phosphorylation of a substrate.
Based on the information presented, which of the following best explains why the researchers measured oxygen consumption as an indicator of the effectiveness of drug X? A Oxygen provides the source of electrons for cellular respiration and is necessary for energy production. B Oxygen consumption increases the mutation rate and causes cells to become cancerous. C Oxygen activates apoptosis, which results in the death of melanoma cells. D Oxygen accepts electrons in oxidative phosphorylation, a process necessary for melanoma cell survival.
Oxygen accepts electrons in oxidative phosphorylation, a process necessary for melanoma cell survival.
Based on the data shown, changes in the light intensity resulted in changes in the rate of which of the following processes? A Excretion B Photosynthesis C Respiration D Translation E Transcription
Photosynthesis
What most likely causes the trends in oxygen concentration shown in the graph above? A The water becomes colder at night and thus holds more oxygen. B Respiration in most organisms increases at night. C More organisms are respiring at night than during the day. D Photosynthesis produces more oxygen than is consumed by respiration during the day.
Photosynthesis produces more oxygen than is consumed by respiration during the day.
Which of the following experimental designs should the students use as a control for the experiment? A Place a catalase-soaked disk in a beaker of water. B Drop the disks from different heights into the solution. C Poke the floating disks back down to the bottom of the beaker and retime the rise of the disks. D Shake the beakers during the time the disks are rising. E Dip the disks in the 5% solution before putting them in any other solution.
Place a catalase-soaked disk in a beaker of water.
A researcher is investigating the effects of a chemical that makes thylakoid membranes permeable to hydrogen ions (H+). Which of the following is the most likely direct effect of adding the chemical to plant cells? A The plant cells will produce less NADPH. B The chloroplasts will generate less ATP. C Chlorophyll will require less light energy to excite its electrons. D The plant cells will split fewer water molecules into hydrogen ions and oxygen.
The chloroplasts will generate less ATPATP.
Which of the following best explains why freshwater fish do not convert ammonia to urea for excretion? A The metabolic pathways of fish do not normally involve nitrogen consumption. B The dilution of ammonia by direct excretion into freshwater conserves energy. C Ammonia is concentrated in tissues, where it is stored prior to excretion. D The nitrogen in ammonia is recycled for use in protein and nucleotide synthesis.
The dilution of ammonia by direct excretion into freshwater conserves energy.
On average, more ATP can be produced from an NADH molecule than can be produced from a molecule of FADH2. Based on Figure 1, which of the following best explains the difference in ATP production between these two molecules? A NADH contributes more electrons to the electron transport chain than FADH2 does and therefore provides more energy to pump protons. B The electrons of FADH2 are transferred through three complexes of the electron transport chain whereas those of NADH are transferred through all four complexes. C FADH2 contributes more protons to the mitochondrial matrix, which decreases the proton gradient. D The protons contributed by FADH2 are combined with O2 to make water and are not pumped across the membrane.
The electrons of FADH2 are transferred through three complexes of the electron transport chain whereas those of NADH are transferred through all four complexes.
Which of the following best describes why the disks rose to the surface faster in the more concentrated hydrogen peroxide solutions? A There was more enzyme present in the more concentrated solutions. B A greater amount of heat was generated in the more concentrated solutions. C The more concentrated solutions lowered the activation energy of the reaction. D The higher substrate concentrations in the more concentrated solutions speeded the reaction. E The density of the water was lower in the more concentrated solutions.
The higher substrate concentrations in the more concentrated solutions speeded the reaction.
Which of the following best describes the cellular location where pyruvate dehydrogenase is most likely active? A The cytosol B The lysosomes C The nucleus D The mitochondrial matrix
The mitochondrial matrix
Two nutrient solutions are maintained at the same pH. Actively respiring mitochondria are isolated and placed into each of the two solutions. Oxygen gas is bubbled into one solution. The other solution is depleted of available oxygen. Which of the following best explains why ATP production is greater in the tube with oxygen than in the tube without oxygen? A The rate of proton pumping across the inner mitochondrial membrane is lower in the sample without oxygen. B Electron transport is reduced in the absence of a plasma membrane. C In the absence of oxygen, oxidative phosphorylation produces more ATP than does fermentation. D In the presence of oxygen, glycolysis produces more ATP than in the absence of oxygen.
The rate of proton pumping across the inner mitochondrial membrane is lower in the sample without oxygen.
Which of the following pieces of experimental evidence best supports the claim that the synthesis of aconitase is controlled by a mechanism similar to ferritin regulation? A IRP binds to aconitase mRNA in the presence of iron. B The relative amount of aconitase protein increases in the presence of high levels of iron. C Oxygen consumption by cells increases in the presence of high levels of iron. D The levels of reduced electron carriers, NADH and FADH2, increase in the presence of high levels of iron.
The relative amount of aconitase protein increases in the presence of high levels of iron.
Which of the following statements best helps explain the reaction specificity of an enzyme? A The free energy of the reactants is greater than the free energy of the products. B The equilibrium constant of the reaction is much greater than 1. C The shape and charge of the substrates are compatible with the active site of the enzyme. D The concentration of the enzyme inside living cells is greater than the concentration of substrate
The shape and charge of the substrates are compatible with the active site of the enzyme.
Which of the following best describes why ice was used during this experiment? A To increase the activity of the enzyme B To retard the breakdown of the catalase C To purge the solution of excess air trapped during blending D To slow the catalase molecules to increase the probability of contact with the hydrogen peroxide molecules E To increase the size of the active site on the enzyme
To retard the breakdown of the catalase
Based on the data in the table, which of the following best explains the effects of rotenone on cellular respiration? A Rotenone acts as an inhibitor of the enzymes in the Krebs cycle. B NADH, produced during glycolysis, is not able to enter the mitochondria because transport proteins are blocked from entering. C Treated cells are not able to break down NADH because certain enzymes of the electron transport chain are inhibited. D Rotenone acts as an allosteric inhibitor of glycolytic enzymes, thus inhibiting cellular respiration.
Treated cells are not able to break down NADH because certain enzymes of the electron transport chain are inhibited.
Which of the following best describes the role of water in photosynthesis? A Water is the only source of protons for the formation of a proton gradient. B Water molecules donate electrons to the electron transport chain. C Water molecules combine with stored carbon molecules to produce glucose. D Water is the terminal electron acceptor for electrons that pass through the electron transport chain.
Water molecules donate electrons to the electron transport chain.
According to the results of this experiment, germination of tobacco seeds during the first week is A increased by exposure to light B unaffected by light intensity C prevented by paper towels D accelerated in green-leaved seedlings
increased by exposure to light
ATP serves as a common energy source for organisms because A it is the smallest energy molecule B it stores the least energy of any energy source C its energy can be easily transferred to do cellular work D it is extremely stable and can be stored in the cell for long periods of time E traces of it have been found in fossils of ancient organisms dating back to the beginning of life on Earth
its energy can be easily transferred to do cellular work
The fact that each line on the graph rises from left to right means that A higher temperatures produce higher rates of metabolism B there were more large fish in the samples taken at high temperatures C larger fish consume more oxygen than smaller fish at all four temperatures D when measurements are taken for larger fish late in the day, observed values are higher E larger fish prefer to live at higher temperatures than do smaller fish
larger fish consume more oxygen than smaller fish at all four temperatures
If the experiment is repeated at pH 11, the observed activity level of the enzyme will most likely be A the same as the level at pH 7 B lower than the level at pH 9 C greater than the level at pH 9 D between the levels observed at pH 5 and pH 7.
lower than the level at pH 9
Which of the following was the dependent variable in the researcher's experiment? A Time B pH C Glucose concentration D Lactic acid concentration
pH
