GCSE OSMOSIS PRACTICAL COURSEWORK

Authors Avatar

Momena Khanum                                                              Teacher: - Barry Brinklow

                 OSMOSIS PRACTICAL COURSEWORK

       Investigation of the concentration and the effect of sucrose on                        

                          Osmosis in apple and potato tissues

INTRODUCTION: -

I will be doing an investigation on the topic of Osmosis (A special type of diffusion).

The aim of this experiment is to investigate the effect of sucrose concentration on osmosis in apple and potato tissues, to find out how the concentration of sucrose solution affects the mass of potato and apple strips. So therefore to find out about the uptake of water into a cell which depends on two main factors, which are: -

  • The water concentration of the solution
  • The water concentration of the cell sap in the vacuole.

Diffusion is a movement of particles from an area of higher to the area of lower concentration, (by random motion). Osmosis is also a special case of movement of water, from a higher to a lower water concentration across a selectively permeable cell membrane until it reaches the equilibrium.

The process of osmosis makes plant cells swell up as you can see in the diagram below which shows a higher water concentration outside the turgid cell, whereas on the plasmolysed cell there is lower water concentration outside. If a lot of the water leaves the cell, the cytoplasm begins to peel away from the cell wall; this process is called plasmolysis. This happens when the water moves into the plant cell’s vacuole and pushes against the cell wall. In this case the functions of the cell wall prevent the cell from bursting out. The process of osmosis takes part in the root of the plant cell, which takes in water from the soil by osmosis. This leads the water to move along the root cell into the leaf, and so therefore the water constantly moves to areas of lower water concentrations.

Join now!

The process of osmosis also occurs in animal cells, but in an animal cell there isn’t any cell wall to prevent them from swelling. This means if they were to be placed in pure water, they would take in water by osmosis up until they burst, that is called haemolysis, which occurs only in red blood cells.

PREDICTION (HYPOTHESIS): -

I predict that the mass of the apple and the potato tissue may increase (rise) in water and dilute concentrations of sucrose depending on the concentration of sucrose inside ...

This is a preview of the whole essay