Photorespiration, C4, CAM (Q2) Flashcards
When do the plant’s stomata close or shrink?
During hot or dry days
When the stomata closes, there is a decline in ______ and increase in ______.
CO2, O2
High temperature means there is more ______ than ______.
O2, CO2
Low temperature means there is more ______ than ______.
CO2, O2
Product of RuBP and O2 that is toxic to plants and inhibits distinct reactions in the Calvin cycle
2-phosphoglycolate
Process that uses ATP but does not generate it; does not produce sugar and loses CO2 instead of fixing it
Photorespiration
Three benefits of photorespiration
- Photoprotective effects
- Maintaining redox balance in cells
- Support plant immune defenses
Why is it called C4 Photosynthesis?
Because the first stable molecule formed is a 4-carbon organic acid called malate
Where can C4 plants be found?
Hot habitats
Two kinds of leaf cells involved in C4 Photosynthesis
- Mesophyll cell
- Bundle sheath cell
Special structure in the leaves of C4 plants where the tissue equivalent to spongy mesophyll cells is clustered in a ring around the leaf veins outside the bundle sheath cells
Kranz anatomy
What enzyme is responsible for adding CO2 to phosphoenolpyruvate (PEP) to form a 4-carbon compound?
PEP carboxylase
What is the four-carbon compound produced in C4 photosynthesis?
Oxaloacetate
The four-carbon compound produced in C4 is reduced with the help of NADH and enzyme malate dehydrogenase. What is produced in this process?
Malate
In C4 photosynthesis, how does the four-carbon compound produced move from the mesophyll cell to the bundle sheath cell?
Via the plasmodesmata
What is the enzyme responsible for turning malate into pyruvate and for releasing CO2 to used by the Calvin cycle?
NAD-malic enzyme/malate dehydrogenase
What enzyme turns pyruvate into phosphoenolpyruvate?
Pyruvate phosphate dikinase
In producing one glucose molecule, how many ATP molecules is required in C4 photosynthesis?
30 (18 in normal photosynthesis + 12)
C4 photosynthesis is commonly observed in tropical plants that thrive in well-watered habitats. These plants are also known as ______.
Mesophytic plants
What is the goal of C4 photosynthesis?
To reduce photorespiration by increasing CO2
What does CAM photosynthesis stand for?
Crassulacean acid metabolism
During nighttime, what happens to the stomata of CAM plants?
The stomata is open and takes CO2
During daytime, what happens to the stomata of CAM plants?
The stomata is close and conserves water.
In what leaf cell does CAM photosynthesis take place?
Mesophyll cell
C4 or CAM: More energy efficient?
C4
C4 or CAM: Best in water conservation
CAM
CAM photosynthesis were first observed in Crassulaceae plants. This type of photosynthesis is typically used by plants that are adapted to very dry environments. These plants are also known as ______.
Xerophytic plants
In producing one glucose molecule, how many ATP molecules is required in CAM photosynthesis?
39 ATP
C4 or CAM: Corn, sugarcane
C4
C4 or CAM: Cacti, agave, pineapple, succulents
CAM
