Microorganisms are grown in large fermenters to produce useful biological products. Explain why the conditions inside an industrial fermenter must be carefully controlled to maximise the yield of product.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Industrial fermenters are large vessels used to grow microorganisms such as yeast or bacteria on a large scale. The conditions inside the fermenter are monitored and adjusted continuously during the process.
Model answer (5 marks)
Temperature must be kept at the optimum for the microorganism, because enzymes work best at this temperature, so metabolism and reproduction are maximised.
Oxygen and nutrients such as glucose must be supplied and monitored, so the cells can respire and grow at the maximum rate.
pH must be controlled, because enzymes are sensitive to pH and will denature if the pH is too high or too low, reducing the efficiency of the metabolic pathways.
These conditions maximise the yield of the desired product by ensuring the microorganisms grow and produce the product as efficiently as possible.
Oxygen and nutrients such as glucose must be supplied and monitored, so the cells can respire and grow at the maximum rate.
pH must be controlled, because enzymes are sensitive to pH and will denature if the pH is too high or too low, reducing the efficiency of the metabolic pathways.
These conditions maximise the yield of the desired product by ensuring the microorganisms grow and produce the product as efficiently as possible.
Examiner tips
- Use the word ‘optimum’ for temperature and pH, as the mark scheme expects this terminology.
- Show the link between enzyme activity and the growth rate of the microorganism.
- Mention that oxygen and nutrient supply is required for respiration and cell division.
- Keep the answer concise – each point should be a short sentence or two.
Common mistakes
- Writing that temperature ‘doesn’t matter’ or that any temperature will work. Failing to mention the link between enzyme activity and growth. Using vague terms such as ‘good conditions’ instead of specifying temperature, pH, oxygen and nutrients.
Mark scheme (5 marks)
- Temperature must be controlled / kept at an optimum temperature
- Because enzymes in the microorganism work best / fastest at the optimum temperature (so metabolism / reproduction is maximised)
- Oxygen / nutrient supply (e.g. glucose) must be maintained / monitored
- So that the microorganisms can respire / grow and reproduce at the maximum rate
- pH must be controlled / monitored to keep enzymes working efficiently / prevent enzyme denaturation
Key terms in this question
Related
- All Pearson Edexcel A-Level Biology A (9BI0) revision notes →
- How to answer a "Explain" question →
- Decode the mark scheme abbreviations →
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