BIOL 3332 Lecture Notes - Lecture 19: Methanogenesis, Radiant Energy, Endergonic Reaction
17 Nov 2016
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Document Summary
Catabolic processes get energy from breaking down compounds. They use it as a source of electrons also. Fermentation, respiration, photoheterotrophy: inorganic energy sources can also be used. Chemical reactions can be energy releasing or energy requiring: larger complex molecules break down into simpler molecules. Releases energy: simpler molecules form larger complex molecules. Changes in free energy indicate whether a reaction will occur spontaneously or not: if exergonic= - g = energy is released= spontaneous, if endergonic= + g = energy consumed= nonspontaneous, g= h-t s. As energy is released and entropy increases, g is negative. As energy is absorbed and entropy decreases, g is positive. In redox reactions: one element is oxidized while one is reduced: oxidant= becomes reduced. In aerobic reactions oxygen is reduced, in anaerobic reactions nitrate is reduced: anaerobic respiration is different from fermentation. Molecules used to carry energy: atp- hydrolysis and phosphorylation.
