Biology Unit 2: C4 and CAM plants

What are some factors that affect photosynthesis

1. Wavelength

2. Light intesity

3. temp

4. Co2 concentration

5. water avalaibility

C4 plants

photosynthetic pathway is dividen into two types of cells, mesophyll cell and the bundle sheath cell

In C4 plants…

carbon is “fixed” into oxaloacetate by phosphoenolpyruvate caboxylate, oxaloacetate is then converted maltate and is trasnported to the bundle sheath cells

MORE ABOUT C4 plants

Maltate has a carboxyl group removed, pyruvate is made and is transported back to the messophyll cell where it is converted to phosphoenolpyruvate

Fact about bundle sheath cells in c4 plants

are impermeable to co2, a high concentration of co2 equals more effieceincy

Examples of c4 plants

Sugarcane, corn, millet

CAM plants

only one cell, same biolgical pathway as C4

MORE CAM PLANTS

carbon fixation is seperated by time of day, in the night the stomata is open, so CO2 is fixed into malic acid, but in night time the stomata is closed

MORE MORE CAM PLANTS

when enough atp and nadph are made through light dependent reactions (photosystems), maltate exits the vacuole

Examples of CAM plants

Cacti, Orchid, Pineapple

Differences between C4 and CAM plants

• CO2 speration from calvin cycle: C4: Between messophyll and bundle sheath cells CAM: Between day and night time

• Stomata: C4: stomata open at day CAM: stomata open at night

• Best environment: C4: Hot, sunny environments CAM: very hot and dry environments

How does C4 plants and CAM plants keep photosynthesizing in hot and dry temperatures

C4 use spaital seperation, it deso this by doing the carbon fixation in the messohyll cell and the calvin cycle in the bundle sheath cell, this allows the CO2 to be concentrated around the rubisco and reduces photorespiration. CAM plants use temporal seperation, when the stomata is open at night, it does its carbon fixation and stores it as malic acid, then they release it duting the day for the calvin cycle, this mean the stomata can stay closed and it conserves water.