BIO 226 Lecture Notes - Lecture 6: Spectrophotometry, Enterobacteriaceae, Turbidity
20 Sep 2016
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Document Summary
Genetic material is evenly distributed, then a transverse wall separates into two. An initial outgrowth enlarges to cell size and then separates. Generation time: time required for a cell to divide or for the population to double. Most bacteria have generation time of 1-3 hours but some can divide in minutes. Initial # of cells x 2 number of generations = # of cells. Example: if 5 cells were allowed to divide 9x, then: To calculate the # of generations a culture has undergone, cell # must be converted to logarithms. The log of 2 (= 0. 301) is used because one cell divides into 2. Metabolic activity is high because the microbes are adjusting to the new media and they"re kind of preparing to divide. Generation time reaches a minimum and remains constant. Logarithmic plot produces a straight ascending line: at the same rate of growth. Most metabolically active and most susceptible to adverse conditions.
