AP Biology Unit 3 Cellular Energetics Test
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?
6CH12O6
(c) Based on the data, identify the shrubs and data point where the greatest flow of electrons through chloroplast electron transport chains most likely occurs. (From information above)
(Responses may vary)
(d) Predict the effect on shrubs growing in one area if they are treated with a compound that blocks electron flow through the electron transport chains of chloroplast. Provide reasoning to justify your prediction. (From information above)
(Responses may vary)
Biological molecules can be separated by using chromatographic techniques. The diagram above shows the separation of several spinach leaf pigments by paper chromatography. Using the diagram above. Discuss the role of pigments both in capturing light energy and in converting it to the chemical energy of ATP and NADPH. (Roll of pigments in capturing energy. Explain process of converting energy).
(Responses may vary)
Researchers tested the effect of light on the rate of photosynthesis by a species of shrub growing under conditions that differ widely in the amount of available light but where the availability of water and soil nutrients is fairly constant. Under constant temperature, relative humidity, and leaf surface area, the researchers used increasing illumination (measured as photosynthetic photon flux density, the number of photons of wavelengths between 400 and 700 nanometers per unit surface area and unit time) and determined the net photosynthesis (measured by the amount of carbon dioxide fixed per unit surface area and unit time at each illumination) of the shrubs growing in full sun, partial sun, or in shade. (a) Describe how plants absorb photons of light energy.
(Responses may vary)
(b) Using the template, construct an appropriately labeled graph to represent the data in Table 1. (From information above)
(Show all three lines in the graph)
Which of the following describes a metabolic consequence of a shortage of oxygen in muscle cells?
A buildup of lactic acid in the muscle tissue due to fermentation
Gelatin is a protein that is derived from collagen which is found in the bones, skin, and connective tissue of animals. To investigate the ability of various enzymes to digest gelatin, a group of students set up an assay involving camera film. Camera film contains gelatin and appears black when I supposed to light but turns clear as the gelatin gets broken down. The students incubated pieces of exposed camera film in test tubes, each containing one of three different enzyme solutions (trypsin, lipase, or amylase) as indicated in Figure 1. The students recorded the time it took for the enzymes to digest the gelatin in each test tube, turning the film from black to clear. Which of the following would be the most appropriate control for the experiment?
A test tube containing a piece of exposed camera film submerged in water.
A researcher claims that the synthesis of ATP from ADP and inorganic phosphate (Pi) is essential to cellular function. Which of the following statements best helps justify the researcher's claim?
ATP hydrolysis is an energy-releasing reaction that is often coupled with reactions that require an input of energy.
In an experiment, a scientist isolates mitochondria from living cells and suspends them into different buffered Solutions. One solution is maintained at pH 4, while the other solution is maintained at pH 9. The scientist finds that mitochondria in the solution at a pH 4 continue to produce ATP but those in the pH 9 solution do not. The results of the experiment can be used as evidence in support of which of the following scientific claims about mitochondrial activity?
ATP production in mitochondria requires a hydrogen ion gradient that favors movement of protons into the mitochondrial matrix.
A researcher claims that only a portion of the light energy captured by green plants is available for growth and repair. Which of the following observations best helps justify the researcher's claim?
As light energy is converted to chemical energy by metabolic processes, some of the energy of lost as heat.
A researcher claims that increase atmospheric carbon dioxide levels cause increased growth rates in plants. Which of the following statements best supports the researcher's claim?
Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds.
Students in a class measured the mass of various living organisms. They then kept the organisms in the dark for 24 hours before remeasuring them. None of the organisms were provided with nutrients during the 24-hour period. The data are as follows. Which of the following is the best explanation for the pattern of change in mass of the organisms over time?
Cellular Respiration
The figure below illustrates the similarities between ATP synthesis in mitochondria and chloroplasts. The figures can best assist in answering which of the following questions?
Do electron transport chains create a gradient so that ATP synthase can generate ATP?
The diagram below shows energy changes in a specific chemical reaction with and without the addition of an enzyme to the reaction. Which of the following questions can best be answered by the diagram?
Does the addition of an enzyme reduce the activation energy required for a reaction?
The chemical reaction for photosynthesis is 6 C02 + 12 H2O + light energy (yields) C6H12O6 + 6 02 + 6 H2O If the input water is labelled with a radioactive isotope of oxygen, 180, then the oxygen gas released as the reaction proceeded is also labelled with 180. Which of the following is the most likely explanation?
During the light reactions of photosynthesis, water is split, removing electrons and protons and oxygen gas is released.
The enzyme hexokinase catalyzes the conversion of glucose to glucose-6-phosphate, which is an important step in glycolysis. The reaction involves the transfer of a phosphate group from ATP to glucose. Either a glucose molecule or a water molecule can fit in the active site of hexokinase. The presence of a water molecule in the hexokinase's active site would result in the hydrolysis of ATP to ADP instead of the conversion of glucose to glucose-6-phosphate. Which of the following statements best helps explain the reaction specificity of hexokinase?
Glucose has the right shape and charge to cause hexokinase to undergo a structural change needed for catalysis, where is water does not.
Which metabolic process is common to both aerobic cellular respiration and alcoholic fermentation?
Glycolysis
The O2 released during photosynthesis comes from
H2O
Which of the following statements about mitochondrial chemiosmosis is NOT true?
Heat energy is required to establish the electron transport chain.
Graphs representing enzymes sensitive to changes in pH include which of the following?
I, II, and III only
Use the graph for questions 7-9. Enzymes with their highest activity at an alkaline (basic) pH are represented by which of the following graphs?
II only
Thirty corn seedlings of equal size were randomly assigned to one of three treatment groups. At the beginning of the experiment, the plants in group I were dried and the mass was determined. The plants in group II were maintained in light for a week. The plants in group III were maintained in the dark for a week. All conditions, other than light, we're the same for groups II and III. At the end of the week, the plants in group II and III were dried and the mass was determined. The experimental results were provided in the table. To explain the increase in mass of the light-grown plants, identify one inorganic source of new plant mass and connect it to the cellular process underlying the increase in mass.
In order for plants to grow, they needed glucose. (Elaborate)
The rate of oxygen production equaled the rate of oxygen consumption during which of the following periods?
J to K
Catechol, a natural substance found in plants, reacts with oxygen to produce benzoquinone and water, as represented by the chemical equation above. The reaction is catalyzed in plants by the enzyme polyphenol oxidase. Accumulation of benzoquinone in plant tissues results in the gradual appearance of brown color. A student observes that lemon juice (pH 2) slows the browning of apple slices. The student claims that lemon juice slows the browning process by altering the activity of polyphenol oxidase. To test the claim, the student distributed equal amounts of a dilute catechol solution to 6 identical test tubes. The pH of each solution was adjusted as shown in the table, and the initial absorbance was recorded. Equal amounts of polyphenol oxidase were added to each reaction tube. After 10 minutes at room temperature the absorbance of 389 nm light (A389) was measured for each sample. Solutions containing greater concentrations of benzoquinone oxide absorbs more light. The changes in A389 are shown in the table below. Based on the experimental results, estimate the optimal pH of the enzyme. Explain your estimate by connecting the experimental results to the structure and function of proteins.
Optimal pH is 7. (Elaborate)
For the following group of questions (16-18) first study the description of the situation and diagrams and then choose the one best answer to each question following it and fill in the corresponding oval on the answer sheet. A student studied the effects of light intensity on oxygen production in green algae. The algae were suspended in water inside a sealed glass jar, and the jar was placed into a constant-temperature, lightproof box containing a light source. A probe was inserted into the jar to record the concentration of oxygen. The probe was connected to a recording device. The setup is shown below. The student decrease the intensity of the light hourly and recorded the corresponding changes in oxygen concentration. The graph below shows the results from the recording device. Based on the data shown, changes in the light intensity resulted in changes in the rate of which of the following processes?
Photosynthesis
In addition to the pigments commonly associated with photosynthesis, a certain photosynthetic species contains two additional pigment types. Which of the following best supports the claim that this species is better adapted to environmental changes than other photosynthetic species are?
The additional pigments allow the species containing them to harvest energy from wavelength of light that the other photosynthetic species cannot use.
A researcher proposes a model of an enzyme-catalyzed reaction in which a reactant is converted to a product. The model is based on the idea that the reactant passes through a transition state within the enzyme-substrate complex before the reactant is converted to the product. Which of the following statements best helps explain how the enzyme speed up the reaction?
The enzyme's active site binds to and stabilizes transition state, which decreases the activation energy of the reaction.
For the following group of questions (10-12) first study the description of the data and then choose one best answer to each question following it and fill in the corresponding oval on the answer sheet. To study the actions of the enzyme catalase on the hydrogen peroxide, students perform the following experiment. Catalase was extracted from potatoes by blending raw potatoes in a blender with cold distilled water. The filtrate was stored on ice. The following hydrogen peroxide solutions were made: 1 percent, 5 percent, 10 percent, and 15 percent. Filter paper discs were soaked in the catalase filtrate and dropped into beakers containing the various solutions. The activity of the enzyme was measured by the amount of time it took for the disks to float to the surface of the solution on the bubbles produced by the reaction. The following data were obtained. Which of the following best describes why the discs Rose to the surface faster in the more concentrated hydrogen peroxide solutions?
The higher substrate concentrations in the more concentrated solutions speeded the reaction.
A researcher designs an experiment to investigate the effect of environmental temperature on the function of an enzyme. For each trial included in the experiment, the researcher will add the enzyme and its substrate to an aqueous buffer solution and then measure the amount of product formed over 20 minutes. Which of the following must remain the same for all trials of the experiment?
The initial concentration of the substrate
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?
The rate of proton pumping across the inner mitochondrial membrane is lower in the sample without oxygen.
Which of the following statements best helps explain the reaction specificity of an enzyme?
The shape in 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?
To retard the breakdown of the catalase
Which of the following best describes the role of water in photosynthesis?
Water molecules donate electrons to the electron transport chain.
The data presented in the figure below are measurements of the rate of oxygen consumption at differing body masses in a species of fish. Each point represents measurements from a different fish. Measurements were taken at different temperatures. The fact that each line on the graph rises from left to right means that
larger fish consume more oxygen than smaller fish at all four temperatures.
If the potato solution was boiled for 10 minutes and cooled for 10 minutes before being tested, the average time for the disks to float to the surface of the hydrogen peroxide solution would be
more than 30 seconds.
The most likely explanation for the results shown in graph I is that
pH affects the shape of the active site of the enzyme.
Carbohydrate-synthesizing reactions of photosynthesis directly require
products of the light reactions.
During respiration, most ATP is formed as a direct result of the net movement of
protons down a concentration gradient.
