Bioprocess Engineering Flashcards
7 cards from real Agricultural/Bioengineering practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Bioprocess Engineering flashcards as text
In a batch bioreactor, which growth phase is characterized by microorganisms dividing at their maximum specific growth rate?
Answer: Log (exponential) phase
During the log phase, nutrients are abundant and microorganisms divide exponentially at their maximum specific growth rate (μmax).
In the Michaelis-Menten enzyme kinetics equation, what does the Michaelis constant (Km) represent?
Answer: Substrate concentration at half-maximum velocity
Km is the substrate concentration at which the reaction proceeds at half of Vmax, reflecting the affinity between enzyme and substrate.
Which bioreactor type is most widely used in industrial fermentation due to its uniform mixing achieved via mechanical agitation?
Answer: Stirred tank reactor (STR)
The stirred tank reactor uses an impeller for mechanical agitation, providing uniform mixing of nutrients, cells, and oxygen throughout the vessel.
In the oxygen transfer rate equation OTR = kLa(C* − CL), what does the term kLa represent?
Answer: Volumetric mass transfer coefficient
kLa is the volumetric mass transfer coefficient, combining the liquid-film coefficient (kL) with the gas-liquid interfacial area per unit volume (a).
Which chromatography technique separates proteins based on their net surface charge at a given pH?
Answer: Ion exchange chromatography
Ion exchange chromatography retains charged proteins on oppositely charged resin, then elutes them by increasing ionic strength or changing pH.
What is the primary operational advantage of continuous fermentation over batch fermentation?
Answer: Steady-state operation with higher volumetric productivity
Continuous fermentation maintains steady-state conditions by continuously feeding substrate and withdrawing product, achieving higher sustained volumetric productivity than batch processes.
A high Damköhler number (Da >> 1) in a bioprocess indicates that the system is limited by:
Answer: Mass transfer rate
Da = reaction rate / mass transfer rate; when Da >> 1, the biochemical reaction proceeds faster than mass transfer can supply substrate or remove product, making mass transfer the limiting step.