Biology 2601A/B Lecture 11: 2601 Lec 11: Gas Exchange 2 - plants
17 Oct 2015
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Document Summary
Metabolism and photosynthesis are dependent on co2 and o2 exchange with the environment. But this allows diffusion of other gases too: water, water vapour is also a gas, saturated air space in leaf with water. Gp = photosynthesis, pr where rubisco fixes oxygen and releases co2. Almost always have the loss of water through these processes. Cuticle: waxy outer part which prevents loss of water. Surfaces and insides of cells saturated with water therefore air space has a lot of water too. Only way to get co2 in is through pores: low co2 concentration inside leaf b/c photosynthesis, mesophyll cells are sink for co2. Pores in the leaf surface that allow access from the outside to air spaces inside the leaf: >90% of all gas exchange. Open is: good for co2 uptake good when you want to photosynthesize, bad for water loss.
