Unit 3: Photosynthesis

Plants gather energy with light-absorbing molecules called

• thylakoids.

• pigments.

• chloroplasts.

• glucose.

Between which parts of the ATP molecule must the bonds be broken to form an ADP molecule?

• between two of the phosphorous molecules

• between the adenosine and the phosphorous molecules

• between the adenosine and the ribose

• between the ribose and the phosphorous molecules

Plants get the energy they need for photosynthesis by absorbing

• high-energy sugars

• chlorophyll a

• sunlight

• chlorophyll b

The stroma is the region outside the

• chloroplasts.

• plant cells.

• mitochondria.

• thylakoids.

Photosynthesis uses sunlight to convert water and carbon dioxide into

• high-energy sugars and proteins.

• oxygen and high-energy sugars.

• oxygen and carbon.

• ATP and oxygen.

What are the three parts of an ATP molecule?

• adenine, ribose, and three phosphate groups

• adenine, thylakoid, and a phosphate group

• stroma, grana, and chlorophyll

• NADH, NADPH, and FADH₂

Energy is released from ATP when

• a phosphate group is added.

• adenine bonds to ribose.

• ATP is exposed to sunlight.

• a phosphate group is removed.

What happens when chlorophyll is struck by sunlight?

• A chemical reaction turns chlorophyll into high energy carbohydrates.

• Energy from fat molecules is released.

• The electrons in the chlorophyll molecule become energized.

• The chlorophyll molecule is broken into two parts.

Which structure in the figure above represents a single thylakoid?

• Structure A

• Structure B

• Structure C

• Structure D

If carbon dioxide is completely removed from a plant's environment, what would you expect to happen to the plant's production of high-energy sugars?

• More sugars will be produced.

• The same number of sugars will be produced but without carbon dioxide.

• No sugars will be produced.

• Fewer sugars will be produced at first, but then the plant will recover.