chapter 7

Question 1

Chlorophyll a

Answer 1

• Absorbs mostly blue-violet and red light

- Participates directly in the light reactions

Question 2

Chlorophyll b

Answer 2

• Absorbs mostly blue and orange light

- Participates indirectly in the light reactions

Question 3

Carotenoids

Answer 3

– Absorb mainly blue-green light
– Participate indirectly in the light reactions
– Absorb and dissipate excessive light energy that might damage
chlorophyll
– The spectacular colors of fall foliage are due partly to the yellow-orange
light reflected from carotenoids.

Question 4

photosystem

Answer 4

a group of chlorophyll and other molecules that
function as a light-gathering antenna

Question 5

What are the Two types of photosystems that cooperate in the light reactions

Answer 5

• The water-splitting photosystem

- The NADPH-producing photosystem

Question 6

thylakoid membrane

Answer 6

where light reactions are located

Question 7

Calvin cycle

Answer 7

– Functions like a sugar factory within the stroma of a chloroplast
– Regenerates the starting material with each turn

Question 8

C3 plants

Answer 8

Use CO2 directly from the air
– Are very common and widely distributed
– Called C3 because it makes G3P, a 3 C compound

Question 9

C4 plants

Answer 9

grasses, corn, sugar cane
– Close their stomata to save water during hot and dry weather
– Can still carry out photosynthesis
– 2 Steps to carrying it out; 2 cell types utilized
– Allows plants to trap CO2 in high light conditions
– Called C4 because it stores CO2 temporarily as a 4 C compound, then
later releases CO2 to go into the Calvin Cycle

Question 10

CAM plants`

Answer 10

Pineapple, Jade plant, cactus
– Are adapted to very dry climates
– Store CO2 similarly to C4 plants
– Open their stomata only at night to conserve water
– Relative Humidity: night vs day

Question 11

What cells use photosynthesis?

Answer 11

plants, some protists, some bacteria

photosynthetic autotrophs/producers for most ecosystems

Question 12

two stages of photosynthesis

Answer 12

light reactions- convert solar to chemical energy

calvin cycle- uses the products of the light reactions to make sugar from carbon dioxide