# Biochemical Engineering Questions and Answers – Cells – Growth Patterns and Kinetics in Batch Culture

This set of Biochemical Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Cells – Growth Patterns and Kinetics in Batch Culture”.

1. How many phases are between growth and death?
a) 4
b) 5
c) 6
d) 7

Explanation: There are six phases in batch growth kinetics. The six phases are: -Lag phase, Acceleration phase, Log phase, Deceleration phase, Stationary phase and Death phase

2. What is the equation used to batch culture growth kinetics?
b) Michealis Menten equation
c) Hardy-Weinberg equation
d) Logistic population equation

Explanation: Monad’s equation is used to determine the batch culture growth kinetics. Monad equation is an expression to study the effect of substrate concentration.

3. At which stages are all the nutrients starting to deplete?
a) Log phase
b) Stationary phase
c) Death phase
d) Lag phase

Explanation: The depletion of the nutrients occurs at the exponential growth phase. This happens because the utilization of nutrients is maximum at this stage for the growth.

4. Which is the phase where the amount of nutrients is less than amount of toxins?
a) Log phase
b) Stationary phase
c) Death phase
d) Lag phase

Explanation: The amount of nutrients is very less at the stationary phase. So, the requirements of the cells are not met and hence the growth medium is completely filled with waste products and toxins.

5. During the death phase the cells not only die but also undergo lysis.
a) True
b) False

Explanation: Death occurs due to the depletion of the energy reserves and the accumulation of toxins. This results in the death of cells and disintegrates at the death phase.

6. Identify the correct Monad’s equation.
a) μ=$$\frac{μ_{max}+[S]}{K_S*[S]}$$

b) μ=$$\frac{μ_{max}*[S]}{K_S*[S]}$$

c) μ=$$\frac{μ_{max}+[S]}{K_S+[S]}$$

d) μ=$$\frac{μ_{max}*[S]}{K_S+[S]}$$

Explanation: The Monad’s equation is μ=$$\frac{μ_{max}*[S]}{K_S+[S]}$$. Where Ks = Monad’s constant, [S] =Concentration of the substrate and µ = rate of growth.

7. What is the rate of cell growth at the log phase?
a) µ = 0
b) µ ≈ µmax
c) µ < µmax+
d) µ > µmax

Explanation: The rate of cell growth at the log phase is approximately equal to µmax. At the log phase the rate of cell growth increases twice.

8. The reciprocal of doubling time is _______
b) Specific growth rate
c) Growth rate
d) Michealis Menten constant

Explanation: The growth rate constant is the reciprocal of the generation time. Doubling time is the time required to double the no. of cells in the culture.

9. What population of bacteria is required to enter the stationary phase?
a) 106cells/ml
b) 107cells/ml
c) 108cells/ml
d) 109cells/ml

Explanation: The number of bacterial cells required to enter the stationary phase is 109cells/ml. At the stationary phase secondary metabolites are produced.

10. Consider one cell will become two in 20 minutes. Then how many will there be after 60 minutes?
a) 4
b) 8
c) 16
d) 32

Explanation: One cell become two in first 20 minutes. In the next 20 minutes it becomes 4 cells. Then in the next 20 minutes these 4 cells will become 8 cells and the overall time required will be 60 minutes.

Sanfoundry Global Education & Learning Series – Biochemical Engineering

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