Biochemical Flashcards
What is generation time?
Time required for a single cell to double
Define doubling time
Time taken for a microbial population to double in number
What is the equation for calculating doubling time?
td = ln(2) / μ
What are the phases of cell growth?
- Lag Phase
- Exponential Growth Phase
- Stationary Phase
- Death Phase
Describe the Lag Phase
- Little increase in cell concentration
- Synthesising transport proteins
- Synthesising enzymes
- Replicating the cell’s genetic material
Describe the Exponential Growth Phase
- Cell’s growth rate is proportional to the cell concentration
- Cells dividing at maximum rate
- Specific growth rate (μ) during this period
Describe the Stationary Phase
- Minimum biological space where lack of one or more nutrients limits cell growth
- Net growth rate is zero
- Antibiotics and other fermentation products produced
Describe the Death Phase
- Decrease in live cell concentration
- Result of the toxic byproducts, harsh environments and/or depletion of nutrient
What is the equation for calculating the rate in the Death Phase?
-rD = KD*Cc
How would you calculate Net Biomass Accumulation?
rGnet = Cc*(μ - KD)
What is the equation for calculating the rate in the Exponential Growth Phase?
rG = μ*Cc
What is the Monod Equation?
rG = (μmaxCcCs)/(Ks + Cs)
What is the Michaelis-Menten Equation?
-rs = (Vmax*Cs)/(Km + Cs)
How would rate be calculated if there were product inhibition?
rG = (1- Cp/Cp)^n * (μmaxCc*Cs)/(Ks + Cs)
Cp* = Product conc at which all metabolism stops
Give the yield coefficient involving cell and substrate values
Mass of new cells formed/Mass of substrate consumed
= -ΔCc / ΔCs
