Agricultural/Bioengineering Bioprocess Engineering

Question 1

In a batch bioreactor, which growth phase is characterized by microorganisms dividing at their maximum specific growth rate?

Accepted Answer

Log (exponential) phase

Answer

Lag phase

Answer

Stationary phase

Answer

Death phase

Question 2

In the Michaelis-Menten enzyme kinetics equation, what does the Michaelis constant (Km) represent?

Accepted Answer

Substrate concentration at half-maximum velocity

Answer

Maximum reaction velocity

Answer

Enzyme concentration at saturation

Answer

Temperature coefficient for enzyme activity

Question 3

Which bioreactor type is most widely used in industrial fermentation due to its uniform mixing achieved via mechanical agitation?

Accepted Answer

Stirred tank reactor (STR)

Answer

Packed bed reactor

Answer

Plug flow reactor

Answer

Fluidized bed reactor

Question 4

In the oxygen transfer rate equation OTR = kLa(C* − CL), what does the term kLa represent?

Accepted Answer

Volumetric mass transfer coefficient

Answer

Dissolved oxygen concentration in the liquid

Answer

Oxygen saturation concentration at the interface

Answer

Oxygen consumption rate by the cells

Question 5

Which chromatography technique separates proteins based on their net surface charge at a given pH?

Accepted Answer

Ion exchange chromatography

Answer

Size exclusion chromatography

Answer

Reverse-phase chromatography

Answer

Hydrophobic interaction chromatography

Question 6

What is the primary operational advantage of continuous fermentation over batch fermentation?

Accepted Answer

Steady-state operation with higher volumetric productivity

Answer

Lower risk of microbial contamination

Answer

Higher product yield per batch cycle

Answer

Simpler equipment design and scale-up

Question 7

A high Damköhler number (Da >> 1) in a bioprocess indicates that the system is limited by:

Accepted Answer

Mass transfer rate

Answer

Reaction kinetics

Answer

Temperature gradients

Answer

pH fluctuations