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Edexcel IGCSE Biology · Spec 5.5-5.8

Microorganisms and Food

How microorganisms are used to make food and drink, including yoghurt and bread, using fermenters.

Biology revision video

Microorganisms and Food

Spec 5.5-5.8

What you need to know

  • Describe the role of yeast in making bread
  • Describe the role of bacteria in making yoghurt
  • Explain how an industrial fermenter works

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Quick check

Answer each question before opening the answer.

What is the role of yeast in bread and in brewing?

Yeast respires anaerobically: the carbon dioxide makes bread rise, and the ethanol is used in brewing.

What is a fermenter used for?

Growing microorganisms under controlled conditions to make products such as yoghurt, penicillin or mycoprotein.

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