C3: In most plants, the first organic product of carbon fixation is a three carbon compound, 3 phosphoglycerate.
Examples of a C3 plant are rice, wheat and soy beans. These plants are important to agriculture. These plants produce less food when their stomatas close due to weather change. The calvin CYcle can no longer function with the declining of the CO2 in the leaves. Instead a process known as photorespiration takes place where oxygen is consumed. No ATP is generated.
C4: They preface the calvin cycle with a different mode of carbon fixation that forms a four carbon compound as its first product. Important members of the C4 plants that are used a lot in agriculture is sugarcane and corn. In C4 plants the two distinct types of photosynthetic cells are bundle sheath cells and mesophyll cells. Their adaptation helps them in hot weather.
CAM : (CAM= Crassulacean Acid Metabolism)Cati and pineapples for example are all water storing plants that open up their stomata during the night and close them during the day . When they close their stomata during the day it prevents carbon dioxide from entering their leaves. The mesophyll cells store the organic acids they make during the night in their vacuoles until the morning.
images:
http://en.wikipedia.org/wiki/File:Calvin-cycle4.svg
http://en.wikipedia.org/wiki/File:Photorespiration_eng.png
http://en.wikipedia.org/wiki/File:C4_photosynthesis_NADP-ME_type.svg
source: " Biology: Sixth Edition" Neil A. Campbell and Jane B. Reece
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