Aim- to see how the body retains certain fluids such as Coke, cafeine free diet coke, bottled water and Gatorade.

Apparatus -

-bleach,

-plastic tub,

-12 X 1000 ml measuring cylinder,

-5 litres of :
Coke;
Cafeine free diet Coke;
Bottled water;
Gatorade.

Procedure
Divide students into 5 groups each with five students selected at random.
Group 1 - Each person in this group will drink 1 litre of Coke in 20 minutes.
Group 2 - Each person in this group will drink 1 litre of cafeine free Diet Coke in 20 minutes.
Group 3 - Each person in this group will drink 1 litre of water in 20 minutes.
Group 4 - Each person in this group will drink 1 litre of Gatorade in 20 minutes.
Group 5 - Each person in this group will not have any liquids.
Measuring cylinders must be washed in a bleach solution after each use.

All participants must empty their bladder before the experiment. To start the experiment all participants , in four of the groups, will drink 1% of their body weight of the specified drink in twenty minutes.

Ask students to make a prediction before the activity.

Enter your results in the Excell spreadsheet provided.

Below is a sample of the results from one group.

Looking at the results

Which liquid is excreted the fastest?

Can we say with certainty that Gatorade is not as well absorbed as water? Explain.

Caffeine is a diuretic. What is a diuretic?

Coke was expected to produce more urine than pure water. Why?

Why is water excreted the most?

What can you conclude from the results?