Cellular respiration is a key concept when studying biology. It is the process in which cells in a plant or animal (or even smaller organisms) convert oxygen into carbon dioxide and water. The easiest way to demonstrate this is with yeast. As a single cell organism, yeast takes in sugar and turns it into carbon dioxide and water. In this experiment, you child will be able to see the results of a chemical reaction that is normally invisible. Here’s how it works:
What you need:
- One empty water or soda bottle
- Warm water
- One teaspoon of sugar
- One balloon
What to do:
- Pour one packet of dry yeast into the bottle. Add about one inch of water to the bottle. Then, add the one teaspoon of sugar. Swirl the mixture around a bit to mix it.
- Stretch out your balloon a bit and then pull the opening over the top of the bottle.
- Observe the balloon every couple of minutes for about 30 minutes. Have your child take note of what happens to the balloon as time goes by. It should blow up gradually as the yeast releases carbon dioxide. The carbon dioxide fills the balloon, forcing it to expand. Pretty simple!