Downstream Processing

Question: 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

Answer: Option A

Explanation:

No answer description available for this question.

Question: The effectiveness of a solvent can be measured by the
[A].

distribution coefficients

[B].

selectivity

[C].

both (a) and (b)

[D].

diffusivity

Answer: Option C

Explanation:

No answer description available for this question.

Question: 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

Answer: Option C

Explanation:

No answer description available for this question.

Question: 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

Answer: Option D

Explanation:

No answer description available for this question.

Question: Which of the following is not the physical method for the cells rupturing?
[A].

Milling

[B].

Homogenization

[C].

Ultrasonication

[D].

Enzymatic digestion

Answer: Option D

Explanation:

No answer description available for this question.

Question: 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

Answer: Option B

Explanation:

No answer description available for this question.

Question: 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

Answer: Option A

Explanation:

No answer description available for this question.

Question: Filtration leaf test results indicate that the filtration rate of a protein product is 100 dry lbs/(ft2 hr). What size production filter would be required to obtain 100 dry lbs of filter cake/hr?
[A].

1.54 ft2

[B].

3.08 ft2

[C].

65 ft2

[D].

65 lbs/ ft2.hr

Answer: Option A

Explanation:

No answer description available for this question.

Question: 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

[C].

Addition of electrolytes

[D].

All of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: 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 L is the thickness of the filter cake)
[A].

(1/A) dVf/dt = Δp/μ(L/K)

[B].

dVf/dt = (1/A)Δp/μ(L/K)

[C].

(1/A) dVf/dt = Δp/μ LK

[D].

dVf/dt = (1/A)Δp/μ LK

Answer: Option A

Explanation:

No answer description available for this question.