Photorespiration, C3, C4, CAM Flashcards
___________ consumes O2 and organic fuel and releases CO2 without producing ATP or sugar
Photorespiration
Photorespiration may be an ________ because rubisco first evolved at a time when the atmosphere had far less O2 and more CO2
evolutionary relic
Photorespiration _____ damaging products of light reactions that build up in the absence of the Calvin cycle
Limits
a hot, dry day it can drain as much as _____ of the carbon fixed by the Calvin cycle
50%
This minimize the cost of photorespiration by incorporating CO2 into four-carbon compounds in mesophyll cells
C4 plants
Location of C4 Method
Mesophyll Cells
What enzyme is required in C4 Plants
PEP carboxylase
What can PEP carboxylase do?
it can fix CO2 even when CO2 concentrations are low
Location where the four-carbon compounds are exported to
Bundle-sheath cells
CAM stands for
Crassulacean acid metabolism
plants that open their stomata at night, incorporating CO2 into organic acids
CAM plants
What happens during the day in CAM plants?
Stomata is closed and CO2 is released from organic acids and used in the Calvin cycle
Examples of CAM plants
Pineapple, cactus
Example of c4 plants
Sugarcane
Spatial Separation of steps
C4 plants
