'Diffusion across a Selectively Permeable membrane Essay\r'

'Introduction:\r\n dispersion is movement of molecules from unrivalled area of concentration to another. This cultivate is vital for the life functions of cells. Cells deport selectively porous membranes that allow only certain solutions to way with them. Osmosis is a special kind of diffusion that allows weewee to go with semi- porous membranes of high body of water system potentiality to a region of lower water potential. irrigate potential measures the t endency of water to leave one place and into another. dispersal and osmosis is responsible for the movement of molecules in and out of cells. dissemination and osmosis can be shown victimization dialysis tubing which is a membrane that is make of regenerated cellulose fibers into a flat tube. When solutions that contain dissolved substances, are free by a membrane like the dialysis tubing, virtually(preno houral) whitethorn readily pass through it and others may not due to the size of the molecules.\r\nHypothesis: \r\nDiffusion and osmosis will occur once dynamic symmetry is reached. If a substance contains molecules subtile enough to pass through a selectively permeable membrane then they will readily pass through it without the solution or substance, which is within the membrane, getting out.\r\nMaterials:\r\n concatenation\r\nStarch Solution\r\nI2KI Solution\r\nPlastic loving cup\r\nDisposable transfer pipettes\r\nStrips of dialysis tubing soaked in water\r\nTimer\r\nScale\r\nMethod:\r\n commencement exercise you will have your dialysis tubing soaked in water ready for the experiment. Once the dialysis tubing in being soaked, wash your hands to get release of each oils or dirt that may be on them. Remove the tubing from the water and obligate absent one end. Open the other end using two fingers in a guide motion so that the tubing will order and open. Use a disposable pipette to miscellanea the tubing with starch solution. Once the tubing is alter leave a bit of space so that e xpansion may occur and tie off the end and place the tubing on the weighing machine to see how much it weighs. Fill the cup with distilled water and add I2KI solution to the water. Place the tubing at heart the cup for 30 proceeding and land any color change. Record the color change of the start every 5 minutes until 30 minutes have passed. Take the tubing out of the water solution and place on the scale and record any weight change.\r\nData:\r\nSolution\r\nsourceOriginal\r\nContentsOriginal\r\ncolorOriginal\r\nWeight5 min\r\ncolor15\r\nmin color25 min\r\ncolor30 min colorFinal weightFinal Contents\r\nBagWater 1% starchWhite/\r\nmilky10gWhite slightly blueMilky wrong darker blue Darker blue some white visibleDarker blue no white visible11gWater 1% starch + iodine BeakerWater, I2KIAmber yellowN/AAmber YellowAmber YellowAmber YellowAmber YellowN/AWater and iodine\r\nResults:\r\nThe results show that the water, glucose, and I2KI molecules were crushed enough to pass through the s electively permeable membrane which was the dialysis tubing. I would expect for the color change to occur in the cup instead of inside of the tubing if we had started with the starch in the cup and the I2KI inside the tubing, because the iodine would instead of going into the bag, would leave through the bag and into the starch inside the cup.\r\nDiscussion and ending:\r\nThe data shows what molecules can and cannot diffuse across a selectively permeable membrane. The color change that occurred showed that the I2KI molecules were lowly enough to pass through the pores of the membrane or dialysis tubing. This data also shows that the water and glucose solution locomote out of the dialysis bag because water molecules are small enough to pass through the membrane. No mistakes were made in this experiment but many could have occurred. If the tubing was not tied correctly a leak could have occurred and the experiment would have failed and been inaccurate.\r\nReferences:\r\nâ€Å"Diff usion and Osmosis.” Diffusion. N.p., n.d. Web. 19 Mar. 2014 â€Å"Diffusion.” And Osmosis. N.p., n.d. Web. 20 Mar. 2014.\r\nâ€Å"Osmosis.” Osmosis. N.p., n.d. Web. 19 Mar. 2014.\r\n'