C4 Photosynthesis Diagram Large Coffee Mug

C4 Photosynthesis : C4 plants. Called C4 because the CO2 is first incorporated into a 4-carbon compound. Stomata are open during the day. Uses PEP Carboxylase for the enzyme involved in the uptake of CO2. This enzyme allows CO2 to be taken into the plant very quickly, and then it "delivers" the CO2 directly to RUBISCO for photsynthesis. Photosynthesis takes place in inner cells (requires special anatomy called Kranz Anatomy) Adaptive Value: Photosynthesizes faster than C3 plants under high light intensity and high temperatures because the CO2 is delivered directly to RUBISCO, not allowing it to grab oxygen and undergo photorespiration. Has better Water Use Efficiency because PEP Carboxylase brings in CO2 faster and so does not need to keep stomata open as much (less water lost by transpiration) for the same amount of CO2 gain for photosynthesis. C4 plants include several thousand species in at least 19 plant families. Example: fourwing saltbush pictured here, corn, and many of our summer annual plants. This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. Author Kelvinsong