⚗️ Biochemical Engineering Solved MCQs with Answers

Practice 513 approved ⚗️ Biochemical Engineering questions with verified answers from the 🧬 Medical Science subject for Pakistan exams.

513 solved MCQs

In a batch reactor specific growth rateAnswer: Changes during the fermentation Turbidostat is recommended when continuous fermentation needs to be carried out atAnswer: High dilution rates near the washout point The advantage of airlift bioreactors over stirred tank bioreactors of a similar size isAnswer: Both (a) and (b) Stirred tank fermenter (STF) can be employed forAnswer: Both (a) and (b) The specific growth rate is affected byAnswer: All of these The main function(s) of a draft tube in an air lift fermenter is/are toAnswer: Distribute shear forces throughout the reactor and minimise bubble coalescence Which of the following is incorrect?Answer: STF can't be used for high viscosity medium The contents in bubble column and air lift reactor are mixed throughAnswer: Compressed air Which of the following statements would be appropriate while comparing bubble column and air lift fermenter of the same size?Answer: All of these During the lag phaseAnswer: Cells synthesize new proteins and membrane components Concentration of the growth limiting substrate meansAnswer: The concentration of the substrate that controls the growth rate of the cells Tower fermentors are used forAnswer: Continuous beer production In wastewater treatment, which bioreactor is generally used?Answer: Trickle bed reactor The contents in stirred tank rector are mixed throughAnswer: A mechanical agitator The height to diameter ratio (H/D) for the tank fermenters isAnswer: <3 The relatively large volume (10 to 40% of total fermenter volume) of the seed culture is employed toAnswer: Decrease the overall fermentation time In an airlift bioreactor, the air sparging region is calledAnswer: Air riser The air riser is located on the outside of the draft tube for the large-scale airlift bioreactors because ofAnswer: Better heat transfer efficiencies At the end of the lag phase, when growth begins, the division rate increases gradually and reaches a maximum value in the exponential growth period. This transitional period is commonly called the accelerated growth phase and is often included as a part of theAnswer: Lag phase Which of the following(s) is/are considered the limitations of the exponential growth model?Answer: It does not consider factors that causes cells growth to stop or slow To describe components of an airlift bioreactor which of the follow-ings are generally included?Answer: Disengagement zone, air riser, downcomer When the height of an aerated bioreactor is increased, it will increase the oxygen transfer rate byAnswer: Increasing the partial pressure of oxygen at the base of the reactor Which of the following is correct for the off-centre impellers?Answer: Off-centre impellers should only be used with reactors with volumes less than 10 m³ The power required by an impeller in a gas sparged system compare to the power required by impeller operating at same speed in a gas free liquid is usuallyAnswer: Lesser Which of the following stirrer requires least amount of energy for same yield?Answer: Intermig A reactor has a total volume of 50,000 litres. If it has a headspace volume of 10,000 litres, then volume of liquid in the reactor will beAnswer: 40,000 l Pure oxygen, if used instead of air will increase oxygen transfer rates becauseAnswer: The saturation concentration of oxygen is higher Higher temperatures affect oxygen transfer rates byAnswer: Increasing Kₗa but lowering C*₀ The Intermig impeller isAnswer: All of these Main reason for using baffles in stirred tank reactors areAnswer: Both (a) and (b)