1.16 Core practical: Osmosis in potatoes + 1.17 percentage gain/loss of mass

Question 1

What is the method for the core practical: osmosis in potatoes?

Answer 1

1- Cut potato into small discs of equal size

2- Dry the potato disks gently with tissue paper to remove excess water

3- Mesure the initial mass of each disk.

4- Place the disks in sucrose solution of different concentrations (1%, 2% etc)

5- Dry with tissue paper again and record the new mass

6- Find the difference in mass and use the percentage change equation to calculate percentage gain or loss of mass.

Question 2

What is an independent variable of the core practical: osmosis in potatoes?

Answer 2

Concentration of sucrose solution

Question 3

What is a dependent variable of the core practical: osmosis in potatoes?

Answer 3

Change in mass of potato disks

Question 4

What is a control variable of the core practical: osmosis in potatoes?

Answer 4

Diameter of the potato disks

Question 5

What is happening in the core practical: osmosis in potatoes?

Answer 5

Water is moving by osmosis from a more dilute solution (in the potato) to a more concentrated solution (sucrose solution) across a selectively permeable membrane (the cell membrane of all potato cells holding water)

Question 6

How do you calculate percentage change?

Answer 6

percentage change = change in mass / start mass X 100