Bioprocess Engineering Multiple Choice Questions on “Production Kinetics in Cell Culture”.
1. Which of the following examples are not related with the class of metabolite, that is “Products directly associated with generation of energy in the cell”?
A. Penicillin
B. Ethanol
C. Acetone
D. Lactic acids
Answer: A
Explanation: Formation of other products such as antibiotics involves reactions far removed from energy metabolism and the class of metabolite related to products for which there is no clear direct or indirect coupling to energy generation has the examples including that of antibiotics such as: Penicillin, streptomycin, vitamins.
2. Which of the following examples are not related with the class of metabolite, that is “Products indirectly associated with energy generation”?
A. Lactic acid
B. Amino acid
C. Nucleotides
D. Citric acid
Answer: A
Explanation: Lactic acid comes under the first category of the class of metabolite that represents products directly associated with generation of energy in the cell. Compounds in the first category are formed directly as end- or by-products of energy metabolism; these materials are synthesised in pathways which produce ATP. Examples include: Ethanol, acetic acid, gluconic acid, acetone, butanol, lactic acid, other products of anaerobic fermentation.
3. Which instrument is used to measure growth kinetics of plant cell lines?
A. Rheometry
B. Spectometry
C. Mass spectrometry
D. Conductometry
Answer: D
Explanation: The conductivity method of measuring growth kinetics of plant cell lines was used especially with the purpose of bioprocess engineering applications of plant cell cultures. The major advantages of using conductometry as the biosensing technique for measurement of plant cell growth kinetics are:
i) The method is very economical and efficient
ii) It gives accurate, reliable and reproducible measurements, while amenable to continuous online monitoring and process control.
iii) It is a noninvasive method which does not adversely affect the plant cells or the bioreactor operation.
4. Which of the following production kinetics is produced at the same time as cell growth?
A. Growth associated
B. Non-growth associated
C. Mixed-growth associated
D. Variable- growth associated
Answer: A
Explanation: Growth associated is produced at the same time as cell growth which constitutes of constitutive enzymes (ones that are normally present) and metabolic intermediates.
5. Which of the following production kinetics takes place during stationary phase?
A. Growth associated
B. Non-growth associated
C. Mixed-growth associated
D. Variable- growth associated
Answer: B
Explanation: Non-growth associated takes place during stationary phase (μ=0) and which constitutes of secondary metabolites such as antibiotics.
6. Maintenance comes under which type of growth kinetics?
A. Growth associated
B. Non-growth associated
C. Mixed-growth associated
D. Variable- growth associated
Answer: B
Explanation: ATP is also required for other activities called maintenance.
– cell motility
– turnover of cellular components
– adjustment of membrane potentials and internal pH
These are non-growth associated mechanisms.
7. Kinetic expressions requires both growth-associated and maintenance-associated production.
A. True
B. False
Answer: A
Explanation: Kinetic expressions requires both growth-associated and maintenance-associated production.
rP = qpx
rP = (YP/X μ + mP)X
qP = (YP/X μ + mP)
Where,
YP/X is the theoretical yield of product from biomass, mp is the specific rate of product formation due to maintenance, and x is biomass concentration.
8. The Theoretical yield is higher than the observed yield.
A. True
B. False
9. Observed yield is better than theoretical yield.
A. True
B. False
Answer: B
Explanation: Effect of incorporating maintenance terms gives observed yield rather than theoretical yields and accounts for unusual behavior, i.e. negative association with growth.
10. The constitutive enzymes are __________
A. Growth associated
B. Non-growth associated
C. Mixed-growth associated
D. Variable- growth associated
Answer: A
Explanation: The constitutive enzymes are growth associated as they are produced at the same time as cell growth. Factors which are required for the growth of the organism is the key aspect.