Bacterial Growth Curve

Phase 1- Lag Phase(A)- The bacterial cell division is just getting started. Generation times are not as rapid as will be during the exponential phase (B). The bacteria are making ATP, cell envelop material, and enzymes, such as DNA polymerase and FtsZ.

Phase 2- Exponential Phase (B)- (log phase) During this phase generation time is shortest, nutrients are abundant-so bacteria are easily able to make all components needed for division.

Phase 3- Stationary Phase- The number of deaths equals the number of new bacteria being made. The bacteria are running out of nutrients, this causes them to not be able to make things needed for cell division, also, they lack food causing cell death.

Phase 4- Death Phase-The number of deaths is greater or equal to the number of new bacteria. Cell division is essentially stopped because the cells are nearly out of food which also results in death of existing bacteria. Suicide is very common during this stage of bacterial growth with high population densities.

Kaci Stoneburner

Thanks for posting this information about the bacterial growth curve and its phases. I had something about this curve in my notes, but your definitions of each phase are more thorough and helped me understand it better. Thanks
Kassie Hein

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