How do c4 plants differ from c3 plants?

How can CAM plants differ from both C3 and C4 plants?

• Answer:

  To understand how CAM plants differ, we must first understand what CAM plants are and how they differ. CAM plants are plants like cacti and pineapples, whose environments are usually dry and hot. When it's really hot, water is actually lost. Without water, photosynthesis cannot function (it has to do with donating electrons to photosystem II for the light reactions of photosynthesis). To counteract this, CAM plants close their stomata during the day. But closing the stomata means there isn't any gas exchange occurring. Without gas exchange, there would be no carbon dioxide (CO2), and thus no photosynthesis (ATP can be produced by the light reactions, but no long term energy storage, 'glucose' is being made) may occur. So the CAM plants open their stomata during the night to intake carbon dioxide. To store it until there is light (thus photons to run the light reactions), CAM plants incorporate the carbon dioxide into a variety of organic acids. During the day, the carbon dioxide is then released and incorporated into sugars in the chloroplasts. This method is called Crassulacean Acid Metabolism or CAM. Long story short, CAM plants differ in the way they attain carbon dioxide. CAM plants open their stomata during the night and during the day, unlike both C3 and C4 plants. They also convert their carbon dioxide into organic acids, unlike C3 (which use CO2 directly) and C4 (which convert CO2 into various 4 carbon molecules first) plants.