Factors the Affect Photosynthesis

1. Light Quality (color)
2. Light intensity
3. Light Period
4. Carbon Dioxide Availability
5. Water Availability

How Gases Enter and Leave Plants

Most common pathway for carbon fixation
Plants that use the Calvin Cycle exclusively
Crops like wheat, rice, and soybeans follow the C3 photosynthetic pathway.
In C3 plants, the enzyme RuBisCO fixes carbon dioxide directly to ribulose-1,5-bisphosphate during the Calvin cycle.
When a plant's stomata are partly closed , the level of CO2 falls (Used in Calvin Cycle), and the Level of O2 RISES (as Light reactions Split Water Molecules).
Low CO2 and high O2 Level inhibits carbon fixing by the Calvin Cycle.

C4 plants, such as corn (maize), sugarcane, and certain grasses, have evolved a more complex photosynthetic pathway to minimize photorespiration.
During the Hottest part of the day, C4 plants have their stomata Partially Closed.
Plants lose only about Half as much Water as C3 plants when producing the same amount of Carbohydrate
C4 plants include corn, sugar cane and crabgrass.

CAM plants, such as succulents (e.g., cacti) and certain orchids, have adapted to arid environments by opening stomata at night to reduce water loss.
During the night, they fix carbon dioxide into organic acids, storing it until daylight when the Calvin cycle occurs.
Minimize water loss through stomata during the day by keeping stomata closed
Suited for desert and other dry environments
Slow growing