Biology 2601A/B Lecture 11: Lecture 11 – Gas Exchange in Plants
3 Dec 2016
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Document Summary
Metabolism and photosynthesis are dependent on co2 and o2 exchange within the environment. Metabolism requires an exchange of oxygen and carbon dioxide with the environment in plants such as animals. Problem with diffusion from stomata: other gases can move back and forth; water. Movement of gases is driven by a gradient of partial pressure. Gases move from regions of high partial pressure to regions of low partial pressure. Physical entrance of gases into plants is through stomata (stoma) Pores that exist in leaf that can open or close and allow access from outside air spaces to inside the leaf. Some gas enters through roots, parts of stem, other pores (< 10%) Ope(cid:374) is good to take up co(cid:1006) (cid:271)ut it"s (cid:271)ad if (cid:449)e (cid:449)a(cid:374)t to restri(cid:272)t (cid:449)ater loss. Movement of gas is passive; if stomata is open then co2 will come in and water will go out. Stomata are located on bottom surface of leaf.
