How Plants Harness Energy

What best describes the role of light in the overall process of photosynthesis?

• Light provides the energy for breaking apart sugars into small molecules.

• Light provides the energy for assembling small molecules into sugars.

• Light accepts the energy that is released by small molecules.

• Light accepts the energy that is released by sugars.

Tags

NGSS.HS-LS1-5

During photosynthesis, what best describes the role of the compound with the chemical formula C6H12O6?

• a product that is not useful because of its low-energy chemical bonds

• a product that is useful because of its high-energy chemical bonds

• a reactant that is useful because of its high-energy chemical bonds

• either a product or a reactant, depending on whether the cell needs to store energy or release energy

Tags

NGSS.HS-LS1-5

NGSS.HS-LS1-6

NGSS.HS-LS2-5

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?

• providing oxygen for sugar molecules

• providing carbon for sugar molecules

• absorbing energy of light & transferring it to electrons

• supplying the energy necessary to assemble sugar molecules

Tags

NGSS.HS-LS1-5

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.

To revise the model, William wants to use color to identify the reactants of photosynthesis. Which labels should he color?

• H2O & O2

• O2 & CO2

• H2O & CO2

• H2O, O2, & CO2

Tags

NGSS.HS-LS1-5

NGSS.HS-LS2-5

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 radiated from the chloroplast during the light-independent reactions.

• Light energy is cycled within the thylakoid.

• The chloroplast reflects the green wavelengths of light.

• Light is the energy source for converting ADP to ATP & NADP+ to NADPH.

Tags

NGSS.HS-LS1-5

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 formation of high-energy sugars

• the cycling of light energy within the photosystems

• the movement of electrons along the electron transport chain

• the conversion of electrons into sunlight

Tags

NGSS.HS-LS1-5

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.

The concentration of hydrogen ions is greater inside the thylakoid than outside. Which reaction or set of reactions releases hydrogen ions inside the thylakoid?

• the break-up of water molecules

• the formation of water molecules

• the break-up of NADPH

• the formation of NADPH

Tags

NGSS.HS-LS1-5

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.)

• All of the matter in water is converted into oxygen gas.

• All of the matter in carbon dioxide is converted into oxygen gas.

• All of the matter in carbon dioxide is converted into sugars.

• Some but not all of the matter in carbon dioxide is converted into sugars.

Tags

NGSS.HS-LS1-6

NGSS.HS-LS2-5

NGSS.HS-PS1-7

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 role of water molecules is to produce _______ & hydrogen ions during the light-dependent reactions.

• carbon dioxide

• electrons

• oxygen

• sugars

Tags

NGSS.HS-LS1-5

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 role of carbon dioxide is to provide matter for ________, which is the main product of photosynthesis.

• carbon monoxide

• electrons

• oxygen

• sugars

Tags

NGSS.HS-LS1-5

NGSS.HS-LS1-6

NGSS.HS-LS2-5