BIO120H1 Lecture Notes - Lecture 16: Evaporative Cooler, Carbon Fixation, C3 Carbon Fixation
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BIO120H1 Full Course Notes
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Autotrophs depend on net photosynthesis = gross photosynthetic products energy used up in respiration, which in turn relies on light, gases and water. Proper functioning requires mild temperature, osmotic balance, enzymes, dissolved nutrient from soil, etc. Any of these factors can limit fitness: plant thermal and water regulation tradeoff and constraint, evaporative cooling is the process that ties heat regulation and water regulation together, generating tradeoffs. To harvest photons, leaves need to have large surface areas. They also need surface area across which gas exchange can take place: co2 in, o2 out. But exposing a large surface area to sunlight immediately puts tissues at risk of heating up to the point where enzymes denature and lose function: plants use evaporative cooling. Water from the leaf"s interior can be evaporated through the stomata. If a plant has an uninterrupted supply of water, the leaf can stay cool despite receiving full sun.
