Core Practical 5 - Beetroot

Question 1

What is the independent variable in CPAC 5

Answer 1

The temperature of the water

Question 2

What is the dependent variable in CPAC 5

Answer 2

The percentage transmission of light

Question 3

Control variables for cpac 5

Answer 3

Time in the water bath - ensuring temp is the only factor effecting the plasma membranes

Size of the beetroot - ensures the rate of diffusion is the same

Colorimeter used - different colorimeters may give different readings

Question 4

What is the method of CPAC 5

Answer 4

-Fill the boiling tubes with 10cm³ distilled water
-Place the boiling tubes into the water baths for 5mins
-Using a cork borer take out a cylinder of beetroot and cut it into even 1cm3
- Add 1 slice of beetroot to the boiling tubes and wait 30 minutes

Callibrate the colorimeter using a distilled eater as a control

5cm³ of each boiling tube should be added intp the colorimeter cuvettes

Test each cuvette individually and record the transmission of light

Question 5

What is the aim of the beetroot experiment

Answer 5

To identify the effect of temperature on membrane permeability