This experiment was performed to inspection the selective permeability of dialysis tubing. The permeability that the tubing to glucose, starch and also iodine (potassium iodide) was tested. The dialysis tubing was clipped to type a bag so the glucose and starch was fed right into the bag with the other end, and was likewise clipped to avoid the seeping that the solution.

Water with number of drops the iodine included to it till it was visibly yellow-amber was included to a 400ml beaker. The bag to be then put in the beaker, which was stirred v a magnetic stirrer. It was left there for 30 minutes. The was viewed that the shade of the systems in the bag changed to blue-black color, this verified that iodine had the ability to pass v the membrane into the bag.

The solution in the beaker ended up being pale yellow-amber, this confirmed that starch didn’t pass v the membrane right into the beaker. To confirm the presence of glucose in the manufacturer and also the bag, a Benedict test was performed on the solutions including tap water (control) too.

The beaker equipment turned right into light brown shade after Benedict equipment was included to it and also suspended in water bath for 10 minutes. The bag solution also readjusted to brown color, if tap water remained blue. This experiment verified that dialysis pipe is selective in that permeability to molecules. It to be permeable to glucose and iodine however not starch.

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PURPOSE: The purpose of the experiment to be to check the permeability the dialysis tubing to glucose, starch and also iodine.


Living cells need to achieve nutrients from your environment and also get rid the waste materials to your surroundings. This exchange of materials between the cell and also its next site is crucial to that existence. Cells have membranes written of a phospholipid bilayer embedded with proteins.

This cabinet membrane can distinguish in between different substances, slowing or hindering the movement of other substances and enabling others to pass through readily. This residential or commercial property of the cell is well-known as selective permeability (Ramlingam, 2008).

Selective permeability is a property of a cell membrane that permits it to control which molecules deserve to pass (moving into and out the the cell) v the pores of the membrane. Selective permeable membranes only allows small molecules such as glucose, amino mountain to conveniently pass through, and also inhibits bigger molecules favor protein, starch, native passing through it.

The dialysis pipe is a semi-permeable membrane tubing provided in separation techniques and also demonstration of diffusion, osmosis, and also movement of molecules throughout a limit membrane (Todd, 2012). That separates liquified substances of various molecular sizes in a solution, and some of the substances may readily pass through the pores of the membrane when others room excluded. The dialysis pipe is consisted of of cellulose fibers. This is shame in a level tube.

In this experiment, the selective permeability the dialysis tubing come glucose, starch and also iodine (potassium iodide) will certainly be tested. This experiment consists of two tests; the test for starch and also the test for reducing sugar. Once iodine (potassium iodide) is added to a equipment in which starch is present, the systems turns blue-black or violet otherwise it remains yellow-amber.

And when Benedict’s reagent is added to a systems in i beg your pardon reducing street is present and also it is boil in a water bath, the solution turns green, yellow, orange, red, and then brick red or brown (with high concentration of sugar present). Otherwise, the solution stays blue.


Will glucose, starch and also iodine (potassium iodide) conveniently pass through the pores the the dialysis tubing?


Glucose, starch and iodine (potassium iodide) will easily pass v the membrane the the dialysis tubing.


The equipment in the bag and also the beaker will certainly both revolve blue-black due to the visibility of iodine and also starch; the presence of glucose in the bag and beaker will be investigated using Benedict test.

MATERIALS: BeakersDialysis TubingTest TubesClipsWater BathWater


Benedict’s reagentGlucoseStarchIodine (Potassium Iodide)


1) 250 ml that tap water was included to a beaker. Number of droppers of Iodine (Potassium Iodide) equipment was added to the water until it to be visibly yellow-amber in color. The shade was climate recorded.

2) The dialysis tubing to be soaked in water because that a few minutes till it started to open. One finish of the bag was folded and also clipped in order to secure it so that no solution seeped through.

3) The other finish of the pipe was opened so the it develops a bag and 4ml that glucose and 3ml of strength was fed right into it. The bag was also closed and its content was mixed. The color of the systems was climate recorded.

4) The external of the bag to be rinsed in tap water.

5) The magnetic stirrer and then the bag was inserted in the beaker. The other finish of the bag to be made to hang over the edge of the beaker.

6) The bag was left in the beaker for around 30 minutes, as the beaker to be being stirred.

7) after 30 minutes, the bag was very closely removed and also made to stand in a dry beaker. The final color of the services was recorded.

8) Benedict test was performed to test because that the presence of reducing street in the equipment in the bag, beaker and tap water (serves as control).

a) 3 test tubes to be labelled control, bag and beaker.b) 2 ml of water was included to the control test tube. 2 ml of the bag solution was added to the bag test tube and also 2 ml the the beaker solution was added to the beaker check tube.c) 2 ml that Benedict’s reagent was included to every test tube and was exposed in a boil water bath because that 10 minutes. The color adjust was recorded.

The systems in the bag rotate blue-black in shade owing to the motion of molecules of iodine native the beaker come the bag which contains starch. The solution in the beaker turn brown after Benedict’s test.

This indicated the visibility of glucose in the beaker. This way that the tubing was permeable to both glucose and also iodine however not starch. The is recognized that strength didn’t pass because the systems in the manufacturer which contains iodine didn’t turn blue-black in color, but remained yellow-amber.


1) How deserve to you define your results?

From the outcomes of the experiment represented in a tabular type above, the hypothesis argued before transporting out the experiment turned out to be incorrect. The dialysis pipe was not permeable to every the 3 solutions- glucose, starch and Iodine (Potassium Iodide). Rather, the tubing to be permeable come glucose and iodine however not starch.

This could be known from the color readjust in the remedies in the beaker and the bag. The tubing to be permeable to iodine and also so the content of the bag turn blue-black in color indicating the existence of starch. Glucose likewise readily passed with the pores that the membrane.

After performing Benedict’s test on the solutions, the bag’s solution and the beaker’s equipment turned brown in color. This mirrors the existence of reducing street in both solutions, meaning that glucose passed into the beaker native the bag.


2) From her results, suspect the dimension of Iodine (Potassium Iodide) family member to Starch.

From the outcomes of this experiment, that is evident that glucose and also iodine (potassium iodide) has actually smaller molecular size than starch. Because starch had larger molecular size, the dialysis tube was no permeable come it (it didn’t permit it to conveniently pass through the pores the its membrane).

3) What colors would certainly you mean if the experiment started with glucose and also iodine (potassium iodide) inside the bag and also starch in the beaker? Explain

* The solution in the bag will stay yellow-amber in color at the finish of the experiment.

* The equipment in the maker will revolve blue-black in shade at the end of the experiment.

* after performing benedict test, both options will turn brown in color.

The systems in the bag remained yellow-amber in color at the finish of the experiment because the dialysis tubing is no permeable to starch and so starch didn’t pass with from the beaker right into the bag.

The systems in the beaker turned blue-black in color at the end of the experiment due to the fact that iodine passed indigenous the bag right into the beaker through the membrane.

After performing Benedict’s check on the bag and beaker solution, both remedies turned brown in color since the tubing to be permeable come glucose, therefore glucose readily passed native the bag right into the beaker through the membrane.


It to be ensured that the right amount of remedies was used in every component of the experiment.It was likewise ensured that the time required for the successful match of the experiment to be adhered to.It was ensured the all apparatus used were tackled with caution.And also, the dialysis tubing to be clipped well on both end to secure that so the no equipment seeped through. CONCLUSION:

It was concluded that the dialysis tubing doesn’t permit all kinds of substances to pass easily through the pores of its membrane. This method that it is selective in the permeability come substances. The dialysis tubing to be permeable come glucose and iodine but not to starch. Starch was excluded due to the fact that it has actually a larger molecular dimension than glucose and iodine.


Ramlingam, S. T. (2008). Modern Biology. Onitsha: African first Publishers.

Todd, I. S. (2012). Dialysis: History, development and Promise.

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