9.3 Photosynthesis

Thylakoids contain clusters of chlorophyll and proteins known as ______________________ . They absorb sunlight and generate high-energy ___________________ that pass along the _____________________.

• chloroplasts, oxygen atoms, outer membrane

• photosynthesis, protons, photosystem chain

• photosystems, electrons, electron transport chain

• stroma, sodium ions, oxygen receptor

Tags

NGSS.HS-LS1-5

NGSS.HS-LS2-5

The light-independent reactions of photosynthesis are also known as _____________________ . During this process, energy from ATP and _______________________

is used to assemble high-energy.

• photosystem I, sugar, proteins

• photosystem II, carbon dioxide, oxygen molecules

• the Calvin cycle, NADPH, sugars

• ATP synthase, water, electron carriers

Tags

NGSS.HS-LS1-6

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 high-energy electrons that accompany the hydrogen ions.

• The energy source is the concentration difference of hydrogen ions across the membrane.

• The energy source is a set of ATP molecules that gather inside the thylakoid.

• There is no energy source; the process occurs without an energy input.

Tags

NGSS.HS-LS1-5

The graph shows how the rates of photosynthesis vary with light intensity for two groups of plants: plants that thrive in direct sunlight, and plants that thrive in the shade. The plants in both groups receive the same amount of water and are kept at the same temperature.

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.

• The rate of photosynthesis increases with light intensity, and it increases without limit.

• The rate of photosynthesis is independent of light intensity, but may be limited by other factors such as water and temperature.

• The rate of photosynthesis is at a maximum over a narrow range of light intensities.

Tags

NGSS.HS-LS1-5

Briana is studying a model of the light-dependent reactions of photosynthesis. The diagram shows a part of this model.

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?

• a wavy arrow that shows Photosystem I

• an equation for the chemical reaction that forms water from hydrogen ions, electrons, and oxygen molecules

• an arrow that shows the electrons moving through electron carriers, and received by NADP+

• an equation for the chemical reaction that forms hydrogen gas from hydrogen ions and electrons

Tags

NGSS.HS-LS1-5

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 high-energy bonds in sugar molecules.

• The energy source is ATP from the light-dependent reactions.

• The energy source is ATP from processes that occur in other organelles of the cell.

• No energy source is used; the process occurs without an energy input.

Tags

NGSS.HS-LS1-5

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?

• Water vapor is used to assemble sugar molecules.

• Carbon dioxide is used to assemble sugar molecules.

• Molecular oxygen is used to assemble sugar molecules.

• Water vapor is released as a waste product.

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NGSS.HS-LS2-5

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?

• generating ATP and NADPH

• removing water from the environment

• adding carbon dioxide to the atmosphere

• adding oxygen to the atmosphere

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NGSS.HS-LS2-3

NGSS.HS-LS2-5

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-dependent reactions, where water molecules are split

• in the light-dependent reactions, where ATP is synthesized

• in the light-independent reactions, where carbon dioxide enters the cycle

• in the light-independent reactions, where 3-carbon sugars exit the cycle

Tags

NGSS.HS-LS1-6