Page 34 - SK Year 6 Science DLP

Let’s
Let’s
Test
Test Microbes Alive!

Can microorganisms Activity 1
breathe?

Aim To show that yeast breathes and releases gas.

Apparatus and Plastic bottle, teaspoon, tablespoon, thread, ruler,
Materials lukewarm water, balloon, yeast, and sugar

Steps
1. Pour 250 ml of lukewarm water into a plastic bottle.
2. Put in three teaspoons of yeast into the bottle.
3. Add one tablespoon of sugar and shake the bottle.
4. Place the balloon over the mouth of the bottle.
5. Observe the size of the balloon.
6. Measure the diameter of the balloon using a thread
and ruler every 5 minutes for a duration of 20 minutes.
7. Discuss your observations in front of the class.

1. What are the changes you observed?
2. State your inference on the changes that you have observed.
3. Why is sugar used in this investigation?
4. What conclusion can you make?

HOTS
HOTS

What is the gas released What will happen if sugar is
during the breathing process of replaced with salt?
microorganisms?

3.1.2
3.1.3
26 3.1.5