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KS3: Useful Microbes

In this lesson, students learn that microbes can be useful, experimenting with Lactobacillus and Streptococcus to make their own yoghurt.

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Learning objectives

All students will:

  • Understand that some microbes can be put to good use
  • Understand that we need bacterial colonisation to live a healthy life

Most students will:

  • Understand that we need to protect our normal microbial flora

Background Information

Bacteria are single-celled organisms and although some of these cause illness and disease, others are helpful and useful. One of the main ways in which bacteria are beneficial is in the food industry. The natural by products created during normal microbial growth are used to make many of the food products we eat everyday.

Fermentation causes a chemical change in foodstuffs. It is a process by which the bacteria break down the complex sugars into simple compounds like carbon dioxide and alcohol. Fermentation changes the product from one food to another.

In this lesson plan, students learn how fermentation microbes are used to create food products and the conditions they need to grow and multiply quickly.

Activities

Main activity:
  • Yoghurt Experiment
Main Activity video
Extension activities:
  • Microscopic Yoghurt
  • Food Production Poster

Curriculum links

PHSE/RHSE:

  • Health and prevention

Science:

  • Working scientifically
  • Scientific attitudes
  • Experimental skills and investigations

Biology:

  • Structure and function of living organisms
  • Cells and organisation
  • Nutrition and digestion
  • Material cycles and energy
  • Cellular respiration

English:

  • Reading
  • Writing

Supporting Materials

Teacher sheets
KS3 Useful Microbes Teacher Guidance
Student worksheets
SW1 Yoghurt Experiment
SW2 Microscopic Yoghurt
Student handouts
SH1 How to Make Yoghurt Instructions