October 5 notes

III. Phases of bacterial growth curve (in culture…not in nature
a. Lag phase—bacterial cell division getting started. Generation times not as rapid as will be during Exponential Phase (b.)
a. Bacteria are making: ATP, cell envelope stuff, enzymes like DNA polymerase, FtsZ….
b. Exponential phase (log phase)—during this phase, generation time is shortest; abundant nutrients
a. → so bacteria easily able to make all components needed for division
c. stationary phase—# of deaths = # of new bacteria. Bacteria running out of nutrients→ unable to make things needed for cell division; also lack of food→ some bacteria dying.
d. Death phase—# of deaths » # of new bacteria
a. Cell division essentially stopped b/c nearly out of food; lack of food also→ deaths of existing bacteria
b. Suicide at high population densities common among bacteria: refer to picture on hand out.

Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License