Ch 9 Review
In both photosystem I and photosystem II, light energy is used to excite electrons. The two photosystems were named in the order of their discovery, and not in the order of their work in the light-dependent reactions. Photosystem II comes first in the sequence of events that moves electrons from water molecules to their destination, NADP+. Hydrogen ions travel with the electrons, and they combine with NADP+ to form NADPH. The process is summarized in this diagram. How is the production of NADPH useful for the process of photosynthesis?
NADPH is critical in transferring hydrogen and energy.
Imagine that y-axis of each graph in Figure 8-6 describes the rate of photosynthesis. Which of the graphs represents the effect of temperature on the rate of photosynthesis?
C
A student prepared two beakers with identical sprigs of a water plant as shown below. She placed one beaker in the shade and the other beaker beside a fluorescent lamp. She then systematically changed the distance from the beaker to the lamp. She counted the bubbles given off by the plants in each beaker. Shown here is the graph of the data for the beaker she placed beside the lamp. Interpret Graphs Look at the graph in Figure 8-10. At what distance from the light source was the greatest number of bubbles produced?
5 cm
Imagine that y-axis of each graph in Figure 8-6 describes the rate of photosynthesis. Which of the graphs represents the effect of light intensity on the rate of photosynthesis?
A
In which experimental setup shown above would you expect the Elodea plant inside the test tube to produce the LEAST amount of oxygen?
A
Compare the storage capacity of ATP and glucose. How does the cell use each of these molecules to store energy?
A glucose molecule can store more than 90 times the energy of a ATP molecules. Glucose is used by cells to store large amounts of energy for large amounts of time. In contrast, ATP is used to store smaller amounts of energy that will be used in the next few seconds. Cells can regenerate ATP from ADP as needed by using the energy from glucose.
Just as animals have evolved, plants have evolved both structurally and metabolically as the environment changed over time. A) Discuss the environmental problems that C3 plants had to deal with that led to the development of both C4 and CAM plants. B) Discuss how C4 and CAM plants structurally and metabolically provided solutions to the problems mentioned in part A.
A) C3 plants needed to adapt to the environment and by doing so they evolved into C4 plants B) C4 plants have chloroplasts which C3 plants to not
The first law of thermodynamics states that energy can be converted from one form to another. A) If the sun is the ultimate source of all energy, trace the chain of energy conversions that must occur from the point at which sunlight strikes Earth's surface to the moment that energy is used to move a human finger. B) At the level of the chloroplast, discuss the energy conversions that must occur from the input of solar energy on a plant to the point at which the plant captures that energy in ATP.
A) The sun shines light onto the earth hitting plants and being absorbed into the plant. From there, that energy is turned into chemical energy and stored in the plant. The human then eats the plant and uses the energy that the plant stored. B) Insert answer here please
Look at Figure 8-12. What are the products of the light-dependent reactions?
ATP, NADPH, and Oxygen
Describe how photosynthesis in CAM plants differs from photosynthesis in more typical plants. Why is it unlikely that you would find a CAM plant in an aquatic environment?
CAM plants don't need water in order to complete the reaction, so they are different from other plants, and an aquatic environment wouldn't be productive for them
A student put together two different experimental setups as shown below. Predict Review the setups in Figure 8-11. Make a prediction about the effect of carbon dioxide on starch production in plants.
Carbon dioxide is one of the critical reactants
Describe the kinds of light that chlorophyll and carotene pigments absorb. What is the advantage for a plant to have more than one kind of pigment?
Chlorophyll absorbs almost all of the wavelengths except glue greens, and greens. Carotenoids don't absorb oranges. The advantage is that the more wavelengths a plant can absorb, the more energy it can potentially create.
What organelle is shown in Figure 8-12?
Chloroplast
Trace the events that occur in the thylakoid membrane during the light-dependent reactions.
Electrons in the pigments in photosystem II absorb energy from light. These electrons then move through the electron transport chain to photosystem I. H+ ions move from the stroma into the inner thylakoid membrane
Yasmine is asked to describe the structural organization of chloroplasts. She writes the following sentence: "A chloroplast contains thylakoid stacks, called stroma, that are surrounded by fluid-filled grana." Which change to the sentence is necessary to make the sentence accurate?
Exchange the positions of "stroma" and "grana."
Discuss the relationship between autotrophs and heterotrophs. Do heterotrophs depend on autotrophs for their survival? Explain your answer.
Heterotrophs cannot produce their own energy so they rely on autotrophs who do produce their own energy for food.
During the light-dependent reactions of photosynthesis, which event must occur for ATP synthase to function properly?
Hydrogen ions must pass through a channel within ATP synthase.
Some people informally call the light-dependent reactions the "light reactions" and the light-independent reactions the "dark reactions." Why is this naming system misleading?
Light independent reactions still use the energy from the light.
William is developing the model shown below to illustrate the process of photosynthesis. He plans to use the model to explain how photosynthesis transforms both energy and matter. The model includes a wavy arrow to show light striking the thylakoids. Which label for the wavy arrow would be MOST USEFUL for communicating the role of light in photosynthesis?
Light is the energy source for converting ADP to ATP, and NADP+ to NADPH.
A research scientist designs an experiment to measure the inputs and outputs of photosynthesis, by mass, for a representative plant over a certain time. The scientist's predictions for the results are shown in the table. The table that the scientist constructed does not include light. Describe the role of light in the scientist's experiment. Then propose an explanation for why light was not included in the table.
Light is the energy source used to convert the inputs into the outputs. The light is what turns the inputs into the outputs.
What BEST describes the role of light in the overall process of photosynthesis?
Light provides the energy for assembling small molecules into sugars.
Which chemical shown in Figure 8-3 is an electron carrier molecule?
NADP+
A student prepared two beakers with identical sprigs of a water plant as shown below. She placed one beaker in the shade and the other beaker beside a fluorescent lamp. She then systematically changed the distance from the beaker to the lamp. She counted the bubbles given off by the plants in each beaker. Shown here is the graph of the data for the beaker she placed beside the lamp. Apply Concepts Look at Figure 8-10. If the student later tested the bubbles collected in the test tube, what would she find they are made of? How do you know?
Oxygen
What process is shown in Figure 8-12?
Photosynthesis
Plants depend on a wide variety of carbon compounds, including carbohydrates, lipids, and proteins. What BEST describes the role of photosynthesis in producing these compounds?
Photosynthesis produces 3-carbon molecules that can be converted into other compounds.
William is developing the model shown below to illustrate the process of photosynthesis. He plans to use the model to explain how photosynthesis transforms both energy and matter. Earth systems include the biosphere, atmosphere, and geosphere. Use the model to explain how photosynthesis acts to transfer carbon between two Earth systems.
Photosynthesis takes carbon from the atmosphere and brings it to the geosphere and into plants.
Which statement is true about a photosystem?
Photosystem II contains a pigment complex that loses electrons which are then replaced by electrons from water.
MY Answers from here on out
Please double check and adjust
A research scientist designs an experiment to measure the inputs and outputs of photosynthesis, by mass, for a representative plant over a certain time. The scientist's predictions for the results are shown in the table. If the scientist's predictions are shown to be accurate, then which conclusion about photosynthesis do they support? (HINT: Apply scientific principles such as the Law of Conservation of Mass.)
Some but not all of the matter in carbon dioxide is converted into sugars.
What are the products of the Calvin cycle shown in Figure 8-12?
Sugar, Carbs, NADP+ and ADP
In Figure 8-12, what provides the carbon needed to make sugars?
The atmosphere
What would occur if there was an excess of NADPH?
The electron from photosystem I would cycle back to photosystem II.
A student prepared two beakers with identical sprigs of a water plant as shown below. She placed one beaker in the shade and the other beaker beside a fluorescent lamp. She then systematically changed the distance from the beaker to the lamp. She counted the bubbles given off by the plants in each beaker. Shown here is the graph of the data for the beaker she placed beside the lamp. Analyze Data Look at the graph in Figure 8-10. What do the student's data show?
The greater the distance from the light source, the less bubbles produced
A student prepared two beakers with identical sprigs of a water plant as shown below. She placed one beaker in the shade and the other beaker beside a fluorescent lamp. She then systematically changed the distance from the beaker to the lamp. She counted the bubbles given off by the plants in each beaker. Shown here is the graph of the data for the beaker she placed beside the lamp. Control Variables In the experiment described in Figure 8-10, which beaker is the student's control?
The one that doesn't change
Researchers have been developing an artificial leaf, a device that mimics the actions of photosynthesis. The artificial leaf harnesses the energy of sunlight and uses it to provide energy for a series of chemical reactions. Potential products include hydrogen gas (H2) and methane gas (CH4). What is one way that the chemical processes of the artificial leaf are similar to photosynthesis?
The products contain high-energy chemical bonds.
A student put together two different experimental setups as shown below. Control Variables Suggest an appropriate control for the experiment shown in Figure 8-11.
The size of the vile and how it is sealed.
Design an Experiment Look at Figure 8-11. What factor is the student varying? What might the student be trying to test? Design an Experiment Look at Figure 8-11. What factor is the student varying? What might the student be trying to test?
The student is varying what is in the vile.
A student put together two different experimental setups as shown below. Predict In Figure 8-11, assume that the student placed Plant A in indirect sunlight for two days. How would the rate of photosynthesis of this plant compare with that of a plant grown under normal conditions?
There wouldn't be enough energy to maximize the amount of sugar and carbs produced.
What BEST describes the roles of photosystem I and photosystem II in the process of photosynthesis?
They absorb sunlight and transfer the energy to electrons.
Under normal conditions, gases diffuse through small holes in the leaves of a plant. When the weather is very hot and dry, plants may close these openings to conserve water. How are the closures most likely to affect photosynthesis?
They decrease the rate of photosynthesis by preventing carbon dioxide from entering the leaf.
How could you prove that the source of the oxygen in a carbohydrate came from CO2 and not H2O?
Use an isotope of oxygen to trace its presence in either water or a carbohydrate
What happens to the electrons in a chlorophyll molecule when light shines on it? Does the chlorophyll molecule ever run out of electrons? Explain your answer.
When energy is absorbed by the electrons in chlorophyll, the electrons increase their energy level and move through the electron transport chain to photosystem 1.
During photosynthesis, what best describes the role of the compound with the chemical formula C6H12O6?
a product that is useful because of its high-energy chemical bonds
The diagram shows the structure of adenosine diphosphate (ADP). What describes the conversion of ADP to ATP?
an input of energy to attach a third phosphate group
A research scientist designs an experiment to measure the inputs and outputs of photosynthesis, by mass, for a representative plant over a certain time. The scientist's predictions for the results are shown in the table. Select the words from the word box below to complete the statements.
carbon dioxide, sugars
Which is the role of the electron transport chain in the process of photosynthesis?
carrying electrons from photosystem II, to photosystem I, to NADP+
Stuart is listing the changes to matter and energy that occur during the process of photosynthesis. Which of these examples should he include in his list?
changes that convert light energy into chemical energy stored in carbohydrates
Nancy is explaining why chlorophyll is classified as a plant pigment and how it is useful in photosynthesis. Which property of chlorophyll would be most appropriate for her to cite?
chlorophyll's ability to absorb light
What is the role of NADP+ in photosynthesis?
electron carrier
A research scientist designs an experiment to measure the inputs and outputs of photosynthesis, by mass, for a representative plant over a certain time. The scientist's predictions for the results are shown in the table. Select the words from the word box below to complete the statements.
electrons, light-dependent reactions
Daniel is developing a model of the light-independent reactions of photosynthesis, also known as the Calvin cycle. How should the model show how carbon compounds enter and exit the cycle?
enter as carbon dioxide, exit as 3-carbon molecules
Describe the activities that take place in the stroma in (a) bright sunlight and in (b) darkness.
in bright sunlight, the Calvin cycle occurs in the stroma. During the Calvin cycle, the products of the light-dependent reactions (ATP and NADPH) are used to convert molecules of CO2 into high-energy sugars.
Identify three factors that affect the rate of photosynthesis and explain the effect of each.
intensity carbon dioxide concentration and also temperature these factors are called limiting factors light is essential for photosynthesis as it. provides the energy to split the water and therefore enable carbon dioxide and water to react no light.
Xavier is describing the role of electron carriers, such as NADP+, in photosynthesis. Which property of NADP+ should Xavier cite?
its ability to accept and release high-energy electrons and a hydrogen ion
Protons (H+) accumulate in the thylakoid space during electron transport between photosystems I and II. The excess of protons in the thylakoid space
moves from the thylakoid space to the stroma through an ATP synthase complex channel that generates ATP
Describe how pigments obtain energy from light. Use chlorophyll as an example of the process you describe.
photosynthetic organisms contain light-absorbing molecules called pigments that absorb only specific wavelengths of visible light, while reflecting others.
A student prepared two beakers with identical sprigs of a water plant as shown below. She placed one beaker in the shade and the other beaker beside a fluorescent lamp. She then systematically changed the distance from the beaker to the lamp. She counted the bubbles given off by the plants in each beaker. Shown here is the graph of the data for the beaker she placed beside the lamp. Predict In the experiment described in Figure 8-10, if the lamp were placed closer than 5 centimeters from the water plant, would the plant give off many more bubbles? Why or why not?
slightly more bubbles, not too many more though.
William is developing the model shown below to illustrate the process of photosynthesis. He plans to use the model to explain how photosynthesis transforms both energy and matter. In a key or legend for the model, how should William describe the roles of NADPH and ATP in the light-independent reactions?
supplying the energy necessary to assemble sugar molecules
In both photosystem I and photosystem II, light energy is used to excite electrons. The two photosystems were named in the order of their discovery, and not in the order of their work in the light-dependent reactions. Photosystem II comes first in the sequence of events that moves electrons from water molecules to their destination, NADP+. Hydrogen ions travel with the electrons, and they combine with NADP+ to form NADPH. The process is summarized in this diagram. In the diagram, an arrow leads from the splitting of water, to the two photosystems, and then to NADP+. What process is represented by this arrow?
the movement of electrons along the electron transport chain
By analyzing this equation, which property of photosynthesis can be identified?
the source of carbon atoms in the carbohydrate product
