Lesson 4.3 Review Questions

Describe three chemical changes that occur during the light-dependent reactions.

Answer explanation

Water is split to release hydrogen ions and molecular oxygen. ADP and NADP+ are converted to ATP and NADPH.

Tags

NGSS.HS-LS1-5

What do plants do with the high-energy sugar molecules they produce during the Calvin Cycle?

Answer explanation

Plants use the sugars to meet their energy needs and to synthesize biomolecules

Tags

NGSS.HS-LS1-5

Assuming there is enough light and water for photosynthesis to occur, explain why a temperature between 0 degrees C and 35 degrees C is still important.

Answer explanation

The enzymes that regulate the reactions of photosynthesis operate best within an arrow range of temperatures. Outside of these temperatures, the enzymes work less effectively, and the reactions of photosynthesis slow or stop.

Tags

NGSS.HS-LS1-3

SEP Develop Models: Draw a model that shows how the six carbon atoms that enter the Clavin cycle as carbon dioxide flow through the cycle.

Answer explanation

Student models should be consistent with the representation of the Calvin cycle in Figure 4-9 and the description in the text.

SEP Construct an Explanation: In a laboratory experiment, a plant receives sunlight and water, but not carbon dioxide. Predict what happens to the plant and construct an explanation for your prediction using what you know about the light-dependent and light-independent reactions.

Answer explanation

The plant dies because it cannot conduct photosynthesis since both the light-independent and light-dependent reactions stop working. Although only the light-independent reactions take up carbon dioxide, they also take part in the cycling of ATP and NADPH. The light-dependent reactions rely on thiscycling, so they would stop working as

well. A process that stops one of the setsof reactions also stops the other

Tags

NGSS.HS-LS1-5

SEP Plan an Investigation: How would you investigate the effect of temperature on photosynthesis? Outline the steps of a practical investigation.

Answer explanation

Grow a photosynthetic plant or algae species keeping all variables identical except for temperature. Compare the rates of photosynthesis by measuring the asses of the plants over time.

SEP Develop Models: Draw a model to illustrate how high-energy sugar molecules produced during the Calvin cycle move through the carbon cycle.

Answer explanation

Student models should show sugar molecules being food for an herbivore, then a carnivore, then decomposers, but also at each step, there should be the release of carbon dioxide from the metabolism of the sugar molecules.

Tags

NGSS.HS-LS2-5