# Q1: The disk centrifuge is the type of centrifuge used most often for bio separations due to its

A continuous operation
B lesser cost
C higher speed
D ease in operation

ANS:B - lesser cost

# Q2: Which of the following is not the physical method for the cells rupturing?

A Milling
B Homogenization
C Ultrasonication
D Enzymatic digestion

ANS:D - Enzymatic digestion

# Q3: The optimum wet solid content for the cell suspension for a bead mill is typically somewhere between

A 5-15% by volume
B 15-30% by volume
C 30-60% by volume
D 60-90% by volume

ANS:C - 30-60% by volume

# Q4: Conventional adsorption is a

A reversible process
B irreversible process
C either reversible or irreversible
D none of these

ANS:A - reversible process

# Q5: Micro filtration refers to the separation of suspended material such as bacteria by using a membrane with spore sizes of

A 0.02 to 10μm
B 1-10A°
C 20-30μm
D 10-200A°

ANS:A - 0.02 to 10μm

When general size range for bacteria is less than 10 micrometer.

How <10 micrometer pore size solves the purpose of filtration?

A 1
B 0
C >1
D <1

ANS:B - 0

A dp>5μm
B dp>10μm
C dp>15μm
D dp>20μm

ANS:B - dp>10μm

# Q8: The purity of a solute collected between two times t1 and t2 during chromatographic separation can be calculated as

A amount of solute eluted - amount of impurity eluted
B amount of solute eluted / amount of impurity eluted
C amount of solvent eluted + amount of impurity eluted
D amount of solvent eluted / amount of impurity eluted

ANS:B - amount of solute eluted / amount of impurity eluted

# Q9: A typical tubular centrifuge has a bowl of 2 to 5 inch in diameter and 9 to 30 inch in height with a maximum rotating speed of

A 15,000 to 50,000 rpm
B 50,000 to 100,000 rpm
C 100,000 to 150,000 rpm
D 150,000 to 200,000 rpm

ANS:A - 15,000 to 50,000 rpm

# Q10: Maintenance cost varies from

A 0-4% of the capital cost
B 12-16% of the capital cost
C 4-8% of the capital cost
D 8-12% of the capital cost

ANS:C - 4-8% of the capital cost

# Q11: Start up expenses in a fermentation industry varies from

A 0-5% of the capital cost
B 10-15% of the capital cost
C 5-10% of the capital cost
D 15-20% of the capital cost

ANS:C - 5-10% of the capital cost

# Q12: Selectivity can be expressed as

A ratio of the distribution coefficients in different solute
B mass fraction of the solute in the extract phase at equilibrium
C mass fraction of the solute in the raffinate phase
D ratio of the mass fraction of the solute in the extract phase to the raffinate phase

ANS:A - ratio of the distribution coefficients in different solute

# Q13: In antibiotic manufacturing processes, the fermentation time ranges from

A 2-3 weeks
B 1-2 weeks
C 4-5 weeks
D 2-4 weeks

ANS:C - 4-5 weeks

# Q14: Concentration polarization can be reduced further by

A pre filtering the solution
B reducing the flow rate per unit membrane surface area
C back washing periodically
D all of the above

ANS:D - all of the above

A 1.54 ft2
B 3.08 ft2
C 65 ft2
D 65 lbs/ ft2.hr

ANS:A - 1.54 ft2

# Q16: The correlation often employed to correlate adsorption data for protein is (where Ymax is the maximum amount of solute adsorbed per mass of adsorbent, X is the mass fraction of solute in the diluent phase in solute-free basis, KL is a constant and Y is the equilibrium value of the mass of solute adsorbed per mass of adsorbent)

A Y = YmaxX/(KL+X)
B YYmax/(KL+X)
C YYmaxX/KL
D Y = YmaxX/ (KL+X)

ANS:A - Y = YmaxX/(KL+X)

# Q17: A common filter medium is the cloth filter generally made of

A canvas
B synthetic fabrics
C metal or glass fiber
D all of these

ANS:D - all of these

# Q18: Which of the following is considered as a pretreatment to the biological feeds?

A Heating to denature the proteins
B Addition of filter aids to increase the porosity
D All of the above

ANS:D - All of the above

A > 1
B < 1
C 1
D zero

ANS:A - > 1

# Q20: Chromatography is based on the

A different rate of movement of the solute in the column
B separation of one solute from other constituents by being captured on the adsorbent
C different rate of movement of the solvent in the column
D any of the above

ANS:A - different rate of movement of the solute in the column

B should be the right answer.

# Q21: The solvent flux across the membrane can be expressed as (where A is the area, Lp is the membrane permeability, σ is the reflection point, Δp is applied pressure and Δπ is the osmotic pressure)

A J = Lpp - σΔπ)
B J/A = Lpp - σΔπ)
C JLp/σΔπ
D J/A = Lpp

ANS:A - J = Lpp - σΔπ)

A 1
B 0
C >1
D <1

ANS:A - 1

# Q23: Assuming the laminar flow across the filter, the rate of filtration (dVf/dt) can be expressed as a function of pressure drop Dp by the modified D'Arcy's equation as (where A is the area of filtering surface, K is the D'Arcy's filter cake permeability and Lis the thickness of the filter cake)

B dVf/dt = (1/A)Δp/μ(L/K)
D dVf/dt = (1/A)Δp/μ LK

# Q24: An ion exchange resin is composed of

A polymeric network
B ionic functional groups
C counter ions
D all of these

ANS:D - all of these

# Q25: The efficiency of cell disruption in a bead mill depends on the

A concentration of the cells
B amount and size of beads
C type and rotational speed of agitation
D all of these

ANS:D - all of these

# Q26: A system which require less solvent and produces a more concentrated extract phase, is desired with a

A large distribution coefficients
B small distribution coefficients
C very small distribution coefficients
D constant distribution coefficients

ANS:A - large distribution coefficients

# Q27: For cost analysis in a fermentor system, the depreciation cost varies from

A 5-6% of the capital cost
B 6-7% of the capital cost
C 6-10% of the capital cost
D 8-10% of the capital cost

ANS:C - 6-10% of the capital cost

How is it 6-10%?

# Q28: Which of the operation does not come under upstream processing?

A Media preparation
B Inoculum development
C Effluent treatment
D Storage of raw material

ANS:C - Effluent treatment

# Q29: The stage wise operation of adsorption is called

A contact filtration
D ion exchange

ANS:A - contact filtration

# Q30: The effectiveness of a solvent can be measured by the

A distribution coefficients
B selectivity
C both (a) and (b)
D diffusivity

ANS:C - both (a) and (b)