This set of Biochemical Engineering Multiple Choice Questions & Answers (MCQs) focuses on “Cells – Ideal Chemostat”.
1. Which parameter can be controlled by the changing the rate of medium added into a chemostat?
a) Growth rate
b) Enzyme activity
c) Specific growth rate
d) Doubling time
View Answer
Explanation: By changing the rate of medium addition we can control the specific growth of the Micro-organisms. The culture volume also remains constant in the chemostat.
2. Which of these parameters are kept constant in an ideal chemostat?
a) pH
b) Cell density
c) Concentration of products
d) pH, cell density, concentration of products
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Explanation: In an ideal chemostat all the parameters are kept constant like pH, concentration of the products, cell density, concentration of the nutrients and etc. Especially the specific growth rate is kept constant.
3. Micro-organisms growing in chemostat attain steady state due to positive feedback.
a) True
b) False
View Answer
Explanation: Micro-organisms follow a negative feedback to attain steady state in a chemostat. This negative feedback is seen between growth rate and nutrient consumption.
4. What is the reason behind negative feedback?
a) Cell growth is less than dilution rate
b) Cell growth is higher than dilution rate
c) Cell growth is equal to the dilution rate
d) Cell growth is less than or equal to dilution rate
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Explanation: The cell growth is higher than dilution rate at the time of negative feedback. The cells grow at a growth rate higher than dilution rate this is because the uptake of nutrients is limited.
5. At steady state the dilution rate is equal to which of these parameters?
a) Specific growth rate
b) Growth rate
c) Doubling time
d) Half life
View Answer
Explanation: At the steady state the specific growth rate is equal to dilution rate. The dilution rate is explained in terms of rate of nutrient exchange.
6. At steady state specific growth rate is inversely proportional to which of these given parameters?
a) Dilution rate
b) Critical dilution rate
c) Doubling time
d) Half life
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Explanation: Specific growth rate is inversely proportional to doubling time. Therefore doubling time can be expressed in terms of dilution rate.
7. Chemostat is frequently used in the manufacturing of which of these given alcohols?
a) Ethanol
b) Methanol
c) Propanol
d) Butanol
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Explanation: Chemostat is frequently used in the production of ethanol. This is also an experimental model for continuous cell culture at a decreasing sugar concentration.
8. What is the main concern while using a chemostat?
a) Rupture of cells while continuous agitation occurs
b) Mixing will not be uniform
c) Cell grow adherent to surfaces
d) Rupture of cells while continuous agitation occurs,Mixing will not be uniform, Cell grow adherent to surfaces
View Answer
Explanation: All of the given options are the major concerns of the chemostat. Foaming, agitaio, aeration are all factors of concern.
9. Dripping of medium into the chemostat results in small impulses.
a) True
b) False
View Answer
Explanation: Dripping of the medium during a reaction in the chemostat results in the formation of small impulses. These impulses affect the static property of the chemostat.
10. What precaution should be taken to avoid breakage of cell by agitation and aeration?
a) Avoid aeration and only allow agitation
b) Avoid agitation and only allow aeration
c) Use of baffles
d) Reduce the speed of the apparatus
View Answer
Explanation: Agitation can be done at a lower rate to avoid breakage of cells. Similarly, antifoam agents, paddles can reduce the concerns regarding the chemostat.
Sanfoundry Global Education & Learning Series – Biochemical Engineering
To practice all areas of Biochemical Engineering, here is complete set of 1000+ Multiple Choice Questions and Answers.
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