Patterns Of Growth Flashcards
What is growth?
The irreversible increase in dry mass that occurs when the rate of synthesis is greater than the rate of break down
What is generation time?
The time taken for a population of unicellular organisms to double in number
What are the 4 phases of growth
Lag
Log(exponential)
Stationary
Death
Viable cell count
Number of cells alive and capable of reproduction
Total Cell Count
All cells dead or alive
Lag phase
Little or no increase in cell number
Cells adjust to growth medium
Enzymes are induced for use in metabolising new substrates
Log Phase
Cells grow and multiply at maximum rate
Stationary phase
Nutrients run out
Secondary metabolites produces by the microbes build up and can have a toxic effect
Rate of production of new cells = death rate of old cells
Death phase
Number of cells dying exceeds the number of new cells being produced
Cells die at a constant rate and may undergo lysis (bursting)
