LIFE 102 Lecture Notes - Lecture 6: Electron Transport Chain, Oxidative Phosphorylation, Citric Acid Cycle
Document Summary
Catabolic pathways yields energy by oxidizing organic fuels. Energy flows into an ecosystem as sunlight and leaves as heat. The breakdown of organic molecules is exergonic. The transfer of electrons during chemical reactions releases energy stored in organic molecules. The release energy is ultimately used to make atp. Chemical reactions that transfer electrons between reactants are called. Oxygen is very electronegative: oxidation-reduction reactions, or redox reactions. In oxidation, a substance loses electrons or is oxidized. In reduction, a substance gains electrons, or is reduced (the amount of positive charge is reduced) Oxidation of organic fuel molecules during cellular respiration. Electrons (cid:396)fall(cid:397) to oxygen - closer to atomic nucleus = lower energy state. As electrons move closer to the nucleus of oxygen, energy is released. During cellular respiration, the fuel (such as glucose) is oxidized, and o2 is. Electrons from organic compounds are usually first transferred to nad+, a.
