BIOL-2356EL Lecture Notes - Lecture 6: Crassulacean Acid Metabolism, Succulent Plant, Rubisco
4 Mar 2020
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Document Summary
Photosynthesis: synthesis of carbohydrates from co2 by green plants using sunlight. Transpiration: loss of water vapour from plants, most via stomata. Evaporation: loss of water vapour, usually through soil surface. Respiration: using organic matter as a source for atp, mostly upon release of co2. To take up co2 for photosynthesis, water is lost by transpiration. (open stomata) Photosynthesis requires light, which causes high temperatures and water evaporation. Open stomata and take up co2 at night. Photosynthesis only occurs in daylight, thus carbon is stored as organic acids. Co2 + phosphoenolpyruvate (pep) --> oaa or malate. Oaa or malate --> co2 + phosphoenolpyruvate and co2 into rubisco cycle. Cam plants fix co2 at night with pep-carboxylase and store it as organic acids until the day when it is converted back and fixed by rubisco sugars as with regular light reactions. Succulence (storage of water) is also an adaptation to drought on its own.
