About 85% percent of the world’s plant species are C3 plants (such as the oranges). In C3 plants, the enzyme rubisco is used to fix CO2 and RuBP into two molecules of 3-PGA (a three carbon molecule). In cool, moist conditions, with a normal light supply, the C3 process of carbon fixation is more efficient than the C4 or CAM process. However, in hot areas, C3 plants are vulnerable to water loss, and closing their stomata to avoid this may lead to harmful levels of O2.
Advertisements