Biology Coursework: an Investigation to Consider the Concentration of a Potato Sap Cell Given Variation of a Concentrated Solution.

7255 Words30 Pages
Biology coursework: An investigation to consider the concentration of a potato sap cell given variation of a concentrated solution. Aim: My investigation is based on the principle of Osmosis: to find and compare water potentials by measuring the gain or loss of mass of the potato. My aim for this investigation is to find the water potential of a potato sap cell and measure the gain or loss of mass (through the process of osmosis in the cells) when leaving consistent samples of potato to ensure precise and accurate results in solutions of varying concentrations of sodium chloride. Secondly I aim to find out if it is possible to work out the potential concentration of the cell sap. You can conduct this investigation using a sodium chloride or glucose solution. I however, have decided to settle with the sodium chloride solution. Cell membrane: Every cell membrane has lipid bilayers (it marks the boundary of the cell). It's called a 'lipid bilayer' because it is comprised of two organised fat layers and this provides the cell membrane structure. A semi-permeable membrane is that of a selective one; only certain molecules can pass through this membrane. However a permeable membrane allows anything to cross the membrane - the opposite of this is the non-permeable membrane (doesn't allow anything to pass through it). It acts like a gate, the semipermeable membrane is for VIP molecules only, the permeable membrane allows anything through and a non-permeable membrane is permanently shut to everything. Diffusion and Osmosis: Osmosis is the movement of water molecules from a higher water potential to a lower water potential across a partially permeable membrane. It is a passive process and does not require energy. Diffusion is the nett movement of particles from where they KATIE McSWINEY PAGE 1! OF !21 are at a higher concentration to a lower

More about Biology Coursework: an Investigation to Consider the Concentration of a Potato Sap Cell Given Variation of a Concentrated Solution.

Open Document