BIOLOGY 2B03 Lecture 4: Post-Translational Targeting (Module 4)
30 Nov 2016
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Document Summary
Interpretation of experimental evidence that supports model of transport. Responsible for oxidative & synthetic functions in cell. Nerve cells- peroxisomes synthesize plasmalogen for cell membranes (which increases insulating capacity of membrane. Liver cells- peroxisome is site of oxidation of toxins (like alcohol) Plant cells- peroxisomes required for conversion of fatty acids into carbohydrates (especially important in seeds which need carbs to power germination) All cells- peroxisomes responsible for catalysis of fatty acids. Catalysis of fatty acids occurs through beta-oxidation (& is required for eventual release of metabolic energy) Animal cells- long fatty acids oxidized to medium chain fatty acids (which are shuttled to mitochondria for further processing) Fatty acids yield most atp on an energy per gram basis. By-product of beta-oxidation is hydrogen peroxide (which is toxic to cells) But, by-products of fatty acid metabolism are toxic. Catalase (which is abundant in peroxisomes) converts toxic hydrogen peroxide to non-toxic oxygen & water molecules.
