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Bmic topic 3.1 - Coggle Diagram

- - - - copying of chromosomal DNA
      - pinch inwards till cell divides into 2
  - - - what happens
        
        Exponential growth rate – cell density doubles every generation
        
        Fastest growth rate, shortest generation time
        
        Optimal growth conditions (sufficient nutrients, no overcrowding)
        
        Straight line in a log graph
        
        Graph of log cell no. vs time shows a straight line
      - prolong log phase
        
        Prolonging Exponential Phase of microbial population growth by:
        
        Subculture into fresh medium
        
        Fed batch – add fresh media
        
        add more nutrients, dilutes metabolic waste
        
        Continuous culture(open system) – culture kept at log phase
        
        fresh media added, spent media removed at the same rate
        
        Volume, cell density, nutrient and wastes levels maintained constant
        Constant rate of cell growth
    - - what happens
        
        Cell growth limited by availability of nutrients, accumulation of toxic metabolic wastes and space
        
        Growth rate = death rate
        
        Cell density remains constant
        
        Cells prepare for competition and/or harsh conditions
    - - what happens
        
        Little or no change in cell density
        
        Cells are adapting to new growth conditions
        
        Need to synthesize necessary enzymes to carry out metabolic processes
        
        Most of the cells are not dividing yet
    - - Very harsh conditions
        
        Toxic metabolic waste>Nutrients
        
        Overcrowding
        
        Death rate > growth rate
        
        Live cell density declines