Microbiology and Immunology 2500A/B Lecture Notes - Lecture 11: Facultative Anaerobic Organism, Obligate Anaerobe, Gram-Negative Bacteria
15 Jan 2017
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Document Summary
The vast majority of bacteria are not pathogens (don"t cause disease) Smallest and simplest (viruses are not included because they are not technically classified as living) Very small compared to their host cells. Estimated there to be 5 x 10 30 prokaryotes on earth. Biomass of all prokaryotic would be about the same as the plant biomass. No nuclear membrane or membrane bound organelles. Daughter cells are identical copies of mother. Stationary: slowing down, running out of nutrients, producing toxic byproducts. Time for one generation to grow and reproduce (thus doubling the population) Some species grow fast (double in ~10 minutes) Some species grow slow (double in ~24 hours) It would make sense for an infectious disease to have a short generation time. Generate large numbers to overwhelm the immune system. Tb is one of the slowest growing bacteria but one of the most successful. Bacteria have evolved this wide range of difference to fit a niche (living environment)
