MCB 2000 Lecture Notes - Lecture 7: Vaucheria Litorea, Sea Slug, Saprotrophic Nutrition
Document Summary
Microbial nutrition: nutrients: process of ac chemical substances from the environment, the absorbed nutrients are used, for energy yielding process, growth, chemical elements absolutely needed, macronutrient : c, h, o, s, p, micro: mn, zn, ni. Sources of essential nutrients: carbon, structural backbone of living matter, 50% of microbial dry weight is c, autotrophs derive c from co2, heterotrophs derive c from organic matter. Heterotrophs: chemoheterotrophs, saprobes derive nutrients from dead organic material, opportunistic pathogen - a saprobe infecting the compromised host, parasites derive nutrients from living organisms, pathogens - harm the host (streptococcus, obligate intracellular parasites (rickettsiae, chlamydiae, viruses) Microbial nutrition: how microbes eat, absorb nutrients that are dissolved, the molecules need to be small, the big molecules are degraded by extracellular enzymes. The movement of molecules across the cell membranes: diffusion - movement of molecules from higher concentration area to lower concentration area, used for transport of small molecules (o2)
