MICB 201 Lecture Notes - Lecture 9: Anaerobic Respiration, Oxidative Phosphorylation, Heterotroph
Document Summary
The heterotrophic way of life, heterotrophs use organic molecules (chx) to satisfy all nutritional requiremenets: carbon, energy, and electrons. Heterotrophs are ubiquitous in nature: found in eukarya lacking chlorophyll, dominates bacterial domain + widely distributed in some archaeal phyla. Most heterotrophs = versatile can use variety of chx sources (dozens) Others = specialized with range of organic molecules they use, eg. methylotrophs most use only 1-c organic molecules as sources, and must build up all other c-containing molecules from them. Versatility + specialization = on spectrum: most important role of heterotrophs = decomposition of organic matter. Decomposition = degradation (fragmentation of organic molecules) + mineralization (organic inorganic form) If no mineralization c, n, s, p would be locked in organic form in dead plants/animals/microbes. Ch-c co2 by decarboxylation (inorganic c for plant use) Ch-n nh4+ by deamination (inorganic n for some plant use) Ch-s h2s by desulfurylation (plant cannot use)
