Investigate the Osmotic Point of Equilibrium in a Potato :: GCSE Biology A2 A-Level Coursework

Investigate the Osmotic Point of Equilibrium in a PotatoThe following Passages are information which I have managed to findwhen researching the topic of Osmosis -The cell membrane controls the movement of substances going into andout of the cells. The cell wherefore controls the Chemical compositionof the internal environment of the cell. It does this in two waysPassive Process - this does not implore energyActive Process - this does require energy to occurThis works in principle which diffusion in which molecules and ions ina solution move from an area of high concentration to an area of lowconcentration resulting in the equal distribution of molecules. Cellsmembranes are selectively or partially permeable, this means movingthe membrane allows certain molecules to pass finished it moving freely go across the concentration gradient but not others.OsmosisThe cell membrane is partially permeable in that it allows somemolecules to diffuse quickly but slows the passing of others.The glucose molecules try to diffuse to the outside but cannot getthrough the membrane because the pores are too small. The watermolecules diffuse trough the pores down the concentration gradient.This membrane- controlled diffusion of water molecuse is controlled byosmosis, it can works both ways so that it can pass into and out ofthe cell.Osmosis and DiffusionIf water is withheld from a flowering plant, the flowers wilt. Ifbacterial cells are placed in concentrated salt water solution, theycollapse and die. Human red blood cells placed in late water expandand burst. These are examples of the effects of osmosis, the fulfilby which water passes through a cell membrane.Osmosis is possible because of the constant state of motion thatexists at the atomic and molecular levels of matter. Specifically, inliquid solutions, molecules of solute (the dissolved substance) andsolvent (the substance, usually liquid, in which the solute isdissolved) move about randomly, spreading from regions of hi ghconcentration into regions of low concentration. This process iscalled diffusion.If a cell membrane allowed an equal passage of solute and solvent,diffusion through the membrane would lead to a cell whose internalcomposition would be indistinguishable to its environment. This does not occurbecause the cell membrane is differentially permeable, orsemipermeable-that is, it is permeable to some molecules but not toothers. Water molecules (and dissolved gases such as atomic number 8 and carbondioxide) pass through the membrane much more readily than dissolvedsolid solutes, such as sugar and salt (see Cell, The Cell membrane).If the environment is hypertonic (having a higher concentration ofsolute than the cell), water diffuses out of the cell.