MICB 201 Chapter Notes - Chapter 12: Exponential Growth, Doubling Time, Sea Salt
Document Summary
Prokaryotes can grow under environmental conditions that were once thought to be inhospitable for life. We can measure how the environment affects prokaryotic growth through their growth rate. Environmental variable can be varying temperature, ph, sea salt etc. Growth isn"t the growth of an individual organism. Semi-closed system (only gas exchange with environment, not with other organisms) Lag phase: population doesn"t increase much in size (getting ready for cell division expressing genes) If they are put into new system with the same environment, the genes are already expressed and there won"t be a lag phase. Exponential growth phase: run out of nutrients or waste product build up. Stationary phase: conditions arise where the population can"t grow anymore. Death phase: if you leave the organisms long enough in an environment, they will eventually die. Expressed as an exponential curve on arithmetic scale. When we are working with prokaryotic population density, we are looking at really big numbers.
