BIOLOGY 2EE3 Lecture Notes - Lecture 14: Root Nodule, Nod Factor, Luteolin
4 Dec 2017
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Document Summary
Animals and microbes have evolved together: some form intricate associations, most are healthy and beneficial, catabolism of cellulose by bacteria in the guts of animals, other associations are unhealthy to one of the partners. Herbivores do not synthesize cellulases they cannot digest cellulose without microorganisms. Parasitism: one species benefits, the other is harmed. Commensalism: one species benefits, the other is unaffected. What is a symbiont: a symbiont has developed a long-standing relationship with another organism (symbiosis) Symbionts- on/in the host: ectosymbionts live on the surface of the host, these do not have to be single-celled organisms. Endosymbionts live within tissues or cells of the host. Consortium of microbes in the intestine: fungal parasitic ectosymbionts athlete"s foot: caused by several fungal species. The plant provides leghemoglobin: binds oxygen (similar to hemoglobin in rbc, prevents oxygen from damaging n2-fixing enzymes. Bacteria provide valuable nitrogen (nh3) to the plant.
