Required Practical 4

Question 1

Describe a method to investigate effect of temperature on permeability of cell surface membrane

Answer 1

• cut equal size cubes of beetroot (same age and type)
• blot on paper towel
• add same number of cubes to 5 different test tubes containing same volume of water
• place each test tube in water bath at different temperature for same length of time
• remove and measure absorbance using colorimeter or prepare dilution series and compare to colour standards

Question 2

Why is the test tube regularly shaken?

Answer 2

• to ensure surfaces remain in contact with liquid
• to maintain a concentration gradient for diffusion