Final answer:
The stationary phase is when the rate of cell production is equal to the rate of cell death, creating a constant culture density. It's distinct from the log phase, where rapid growth occurs and cells are highly susceptible to antibiotics, and from the lag and death phases, which represent the start of cell adaptation and the eventual decline in cell numbers, respectively.
Step-by-step explanation:
The stage during which new cells are being produced at the same rate as other cells are dying is known as the stationary phase. During the stationary phase, the number of live cells reaches a plateau; the rate of cell division is now equivalent to the rate of cell death, resulting in a steady total population of living cells. The culture density in a stationary culture is constant, which represents the culture's carrying capacity or maximum culture density for a given organism under specific conditions.
Comparatively, during the log phase, also known as the exponential growth phase, the cells are actively dividing and their number increases exponentially. This is a period of uniform metabolic activity and is considered the phase where bacterial cells are most susceptible to antibiotics like penicillin, which inhibit cell wall synthesis.
The initial growth period, referred to as the lag phase, is when the cells have been introduced to a fresh culture medium and are preparing for active division but are not yet increasing in number. Finally, the death phase is characterized by a decline in the number of cells due to the accumulation of toxic waste, nutrient exhaustion, and cessation of metabolic activity.