BIOLOGY PEARSON
Which of the following describes the role of photosynthesis in the carbon cycle?
transfer of carbon from the atmosphere to the biosphere
Thylakoids contain clusters of chlorophyll and proteins known as_____________. They absorb sunlight and generate high-energy_________ that pass along the _________________________
photosystems, electrons, electron transport chain
Which statement accurately describes the role of the light-independent reactions?
transferring chemical energy to form high-energy sugars
Photosynthesis converts light energy to stored chemical energy. What best describes the role of molecular oxygen (O2) in this process?
a byproduct that is released into the atmosphere
A student is making a model to illustrate the functions of ADP and ATP in photosynthesis. Which model best illustrates the role of ATP in photosynthesis?
a rechargeable battery that stores and releases energy
Although animals do not perform photosynthesis, their food supply depends on the sugars that photosynthesis produces. What is the other significant benefit to animals that photosynthesis provides?
adding oxygen to the atmosphere
Briana notices the electrons that the water molecules release. She asks, "Will the electrons build up in the chloroplast?" Which addition to the diagram would be most useful for answering Briana's question?
an arrow that shows the electrons moving through electron carriers, and received by NADP+
During photosynthesis, the light-dependent reactions supply ATP to the light-independent reactions. How is ATP used in the light-independent reactions?
ATP provides the chemical energy for the reactions to occur.
In a science experiment, Professor Byron adds heavy water to the soil of a growing plant. The plant takes up and uses heavy water in the same way it would take up normal water. After several days, the professor looks for deuterium in the plant and in the gases that the plant releases. Which is the most likely result of the experiment?
Deuterium is part of plant sugars, lipids, amino acids, and other compounds throughout the plant.
The light-independent reactions of photosynthesis are also known as ___________. During this process, energy from ATP and _______ is used to assemble high-energy _______.
the Calvin cycle, NADPH, sugars
Photosynthesis can be modeled by its overall chemical reaction. Which two compounds are the inputs, or reactants, of this reaction?
carbon dioxide and water
When the light-independent reactions are occurring, gases diffuse between the chloroplast and the air that surrounds the plant. Why is gas diffusion essential during this stage of photosynthesis?
Carbon dioxide is used to assemble sugar molecules.
What is the relationship between the light-dependent reactions and light-independent reactions?
Energy in the form of ATP and NADPH is transferred from the light-dependent reactions to carbohydrates in the light-independent reactions.
During photosynthesis, how is the light energy that strikes the cell transformed into the chemical energy stored in sugars?
Energy is transferred to sugars through intermediates, such as chloroplasts.
During the light-independent reactions of photosynthesis, carbon dioxide is combined with hydrogen to form sugars. What is the energy source, if any, that allows this process to occur?
The energy source is ATP from the light-dependent reactions.
The thylakoid membrane contains a protein called ATP synthase. As hydrogen ions pass through the protein, ADP and a phosphate group are combined to form ATP. What is the direct energy source, if any, for the movement of hydrogen ions and the formation of ATP?
The energy source is the concentration difference of hydrogen ions across the membrane.
The enzyme ATP synthase is a protein that contains a small channel. How is the movement of hydrogen ions through the channel useful in the function of the enzyme?
The movement of hydrogen ions provides the energy for the reaction that forms ATP.
For both groups of plants, what BEST describes the relationship between light intensity and rate of photosynthesis?
The rate of photosynthesis increases with light intensity, and might be limited by other factors such as water and temperature.
During the light-dependent reactions, high-energy electrons are passed from chlorophyll molecules to the electron transport chain. How are water molecules essential for this process to occur?
Water molecules split apart and supply electrons to chlorophyll.
Betel is developing a model of the process of photosynthesis. One of her goals is to identify the products of photosynthesis that will later be used to assemble sugars, lipids, amino acids, and other essential compounds for the organisms. In which part of the model should these products be identified?
in the light-independent reactions, where 3-carbon sugars exit the cycle
