Biomolecules And Enzyme Lab Report

BCH3203 Biochemistry of Biomolecules and Enzymes

January 2016 session

Name: Lim Ying Yuen ID number: I15008498

Title: Dialysis

Introduction:

Dialysis is a process which to removed wasted and unwanted water from the solution through diffusion or osmosis. This process mainly function in our blood vessel and kidneys. It is very important for our body as it helps us to remove any toxins, extra salt and sugar from our body and excrete it as sweat or urea. Our blood vessel and nephrons are semi-permeable which only available specific components to pass through according to its size. The small molecules such as water and ions can pass through the membrane easily while protein will be bounded back from the membrane as it had a larger size than water

During the process of dialysis, reducing sugar, chloride ion, phosphate and calcium ion which are smaller molecule will pass through the semi-permeable membrane from tubing to the dialysate while protein will be left inside the dialysis tubing as it is larger than other ions.

After a long time of dialysis, we will test the dialysate with biuret, benedict, AgNO3 and more to test the component inside the dialysate.

Aims: Learn to dialyse milk in a cellulose dialysis bag and test the external dialysate for some of components of milk such as protein, reducing sugar, chloride ion and more.

Material and method: Refer to BCH203/303/3203 Laboratory Manual January 2016 session, page 39 and page 40.

Test Colour Solution Negative Control Positive control Precipitate for solution Precipitate for negative control Precipitate for positive control

Biuret * colourless Colourless colourless Light blue Light blue Purple-violet

Benedict Blue colourless - Red in blue solution blue -

Chloride Colourless colourless - White precipitate-turbid Colourless -

Phosphate Greenish-yellow greenish Greenish yellow yellow Greenish yellow Lemon yellow

Calcium Pink - - pink - -

Results:

Test Quantity Precipitate for solution Precipitate for negative control Precipitate for positive

They were tested for chloride ions using HNO3 and AgNO3. A positive result occurred which there were large amount of white precipitate which was AgCl formed in the tube contained dialysate but no precipitate do not formed in negative control tube.

From phosphate test, we could observed that it had greenish-yellow solution and slightly yellow precipitate formed in the test tube of solution. The negative tube was just only deionized water which acted as negative control while the another tube will put phosphate control which contained lots of phosphate, acted as positive control. Compared to the other two tubes, negative control and positive control, we can concluded that the dialysate contain phosphate as it had a similar result with the positive tube which had greenish-yellow solution and moderate lemon-yellow precipitate formed in the tube.

In the testing of calcium ion. According to the general knowledge, there should be some calcium oxalate (CaC2O4) in the solution but the result show negative. The main reason that we could not get calcium oxalate from the result maybe is because that we do not dialysis the milk in dialysis tube in long enough