BIOL 202 Lecture 5: Chapter 5: Microbial Growth and Nutrition
20 Feb 2017
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Document Summary
Mass of bacteria are collectively greater than all of plants and animals combined. Asexual binary fission: cell double in mass and size: making all the ribosomes/organelles to later divide them between cells. B-phase: dna replicates circular chromosome and two strand separate. C-phase: division: the septum in between eventually leads to division into two identical cells. Generation/doubling time: the interval of time between binary fissions. Shorter doubling time means shorter incubation period: a good example is food poisoning where disease is caused in mere hours. Bacteria eventually run out of space or become limited in their ability to accept oxygen or remove waste (probably due to the constraints of the environment). Lag phase: no cell division; size growth, nutrient acceptance, dna replication: b and c phases. Log phase: cells are undergoing binary fission; disease symptoms develop during this time: best time to take antibiotics and take biochemical tests. Reproductive and death rates equalize; nutrients become scarce while waste builds up.
