3.5 Continued: Problems For C3 Plants And Adaptations Flashcards
1
Q
What is photorespiration?
A
On very hot days, plants close their stomata to stop water loss
2
Q
Why is photorespiration bad for plants? (3)
A
- causes less CO2 to be present, and more O2
- then Rubisco will bind to O2 and use ATP
- this produces more CO2 but no sugar is produced
(Rubisco binding to O2 is insufficient and wont build the carbs we need)
3
Q
How have plants that live in hot, dry climates evolved to have alternate mechanisms of carbon fixation? Like what type of plants do we have now?
A
- C4 plants
- CAM plants
4
Q
What do C4 plants do? (5)
A
- have spatial separation of steps :compartmentalization
1. stomata partially close to conserve water
2. Mesophyll cells fix CO2 into a 4-C molecule
3. Transferred to bundle sheath cells
4. Releases CO2 to be used in the Calvin Cycle
5
Q
What are examples of C4 plants?
A
- corn, grasses, sugar cane
6
Q
What do CAM plants do to their stomata?
A
- open stomata at night (cooler, less evaporation) and close during the day (hot, increase temp)
7
Q
What do CAM plants do to themselves? (2)
A
- CO2 is incorporated into organic acids and stored in vacuoles ( in mesophyll)
- During the day, light reactions occur and CO2 is released from the organic acids and incorporated into the Calvin Cycle
8
Q
What are examples of CAM plants?
A
Pineapple, cacti, succulents, jade