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Question 17N.3.SL.TZ0.08

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Date November 2017 Marks available [Maximum mark: 6] Reference code 17N.3.SL.TZ0.08
Level SL Paper 3 Time zone TZ0
Command term Explain, Identify, State, Suggest Question number 08 Adapted from N/A
08.
[Maximum mark: 6]
17N.3.SL.TZ0.08

The diagram shows a simplified fermenter used in the production of penicillin.

[Source: Valero, F, del Rio, JL, Poch, M and Sola, C (John Wiley and Sons, 1992). Studies on Lipase Production by Candida rugosa Using On-line Enzymatic Analysis. Annals of the New York Academy of Sciences, 665, pp. 334–344.
doi: 10.1111/j.1749-6632.1992.tb42596.x]

(a)

State two conditions in the fermenter that would be monitored by the probes.

 

[1]

Markscheme

a. pH

b. temperature

c. oxygen levels

d. viscosity

e. foam

f. carbon dioxide

Accept any two conditions for the mark

[Max 1 Mark]

(b)

Suggest a reason that the fermenter is surrounded by a water jacket.

[1]

Markscheme

a. maintain constant temperature/insulation

b. cooling

[Max 1 Mark]

(c)

Identify the waste gas produced.

[1]

Markscheme

carbon dioxide/CO2

(d)

Explain the process of penicillin production in the fermenter.

[3]

Markscheme

a. inside of fermenter is sterilized «to prevent growth of other organisms»

b. «penicillin» fungus/Penicillium added to fermenter

c. nutrients are provided to allow the fungus to grow

d. when nutrients are used up, penicillin is produced

e. penicillin extracted from mixture in fermenter

f. penicillin purified ready for medical use

Accept named nutrient eg: glucose

[Max 3 Marks]