Test 12 Different Aqueous Solutions Containing Macromolecules

1062 Words5 Pages

The purpose of this lab was to test 12 different aqueous solutions containing macromolecules, 11 of which were controls while the final one was an unknown. Three different test were carried on each of the 12 samples. The first was an iodine test for the presents of either starch and glycogen in the sample. Iodine is a clear colourless liquid before being added to any of the solutions. The way starch is identified is by the solution turning blue-black.The solution does this because of the amylose in the starch, amylose and amylopectin are the two parts that make up a starch, amylose is made up of 200 to 5,000 alpha -D-glucose, which coil into a tight spring structure(Toole, 2004). When the iodine is added it is pushed by the starch into the middle of this coil this creates a tight helix and this turns the solution black/ dark blue.(Ophardt, 2003) The way Glycogen is identified is when the solution turns reddish-brown. Glycogen is very similar to amylopectin as it is made up of alpha glucose units joined at 1-4 and 1-6 and it is a branched structure. (Toole, 2004) Iodine affects glycogen similarly as it does amylose.
The second test that is being preformed is the Benedict’s test, this test if for reducing sugars in the solutions. A carbohydrate that has a free aldehyde(carbon double bonded to an oxygen, a hydrogen attached as well as a one open R group) functional group as part of its molecular structure is know as a reducing sugar.(Simon et al, 2015) In the
Get Access