Lecture 3

Question 1

Holoparasite (plants)

Answer 1

have no photosynthetic pigments and get energy from other plants

Question 2

Hemiparasite (plants)

Answer 2

have photosynthetic pigments but obtain nutrients, water, & some energy from a host

Question 3

Light Reactions

Answer 3

harvest sunlight to split H20; provides electrons to make ATP + NADPH

Question 4

Dark Reactions

Answer 4

CO2 is fixed in the calvin cycle; carbohydrates are synthesized

Question 5

Light Compensation Point

Answer 5

point where CO2 uptake is balanced by the loss of CO2 through respiration (zero net photosynthesis)

Question 6

Saturation Point

Answer 6

when photosynthesis no longer increases as light increases

Question 7

Factors affecting photosynthetic rates

Answer 7

local adaptations & nutrients

Question 8

Local adaptations (photosynthetic rates)

Answer 8

plants from different climate zones have enzymes with different optimal temperatures allowing them to operate in that climate

Question 9

Nutrient/Nitrogen trade-off

Answer 9

increase nitrogen in a plant increases the plants photosynthetic rates, but also increases its chance of getting eaten

Question 10

Rubisco two functions

Answer 10

carboxylase (photosynthesis) and oxygenase reaction (photorespiration)

Question 11

Benefits of photorespiration?

Answer 11

protects plants from light damage; NOT advantageous when CO2 levels are low & temperature is high

Question 12

Why is photorespiration not advantageous when CO2 is low and temperature is high?

Answer 12

because rubisco will bind O2 instead of CO2 , decreasing photosynthesis

Question 13

C4 trade-off

Answer 13

C4 requires more ATP but they have an advantage at high temperature because PEPcase can stil bind CO2 even with a closed stomata

Question 14

C4 is ______ separated

Answer 14

spatially

Question 15

CAM is _______ separated

Answer 15

temporally