Macromolecules Lab Report

Through the experiment, it has been confirmed that the victim's last meal was at Avanti's Restaurant. In order to distinguish the possible macromolecules that the victim had ingested before the death, the four experiments were held- lipid test, protein test, glucose test, and starch test.

Firstly, the lipid test was done by checking if the droplets of victim's vomit will appear translucent on the paper tissue when it's dried. The result came out to be translucent, meaning the substance contains lipids.

Secondly, the protein test was held by using the Biuret Reagent to indicate whether the substance contains proteins. The positive test result will show the color change to pink or purple. When Biuret was added into the substance, its colour

turned to grey, which means that it does not contain any proteins.

Nextly, the Glucose(monosaccharides) test was processed, using the Benedicts reagent. This reagent requires 80'c or higher temperature in order to gain a valid result. The positive test result will show the color change to yellow or brown. After leaving the substance in a hot water bath for a reasonable amount of time, the colour did not reach yellow or brown. There isn't any glucose(monosaccharides) in the substance.

Lastly, the starch(polysaccharides) was tested with the iodine. As the result, its color turned black, giving the positive result. It confirms that the starch(polysaccharides) definitely exists in the substance.

After going through the four Organic Macromolecules tests, the case has been unveiled. The vomit is composed of lipids and starches. Among the available choices, only Avanti's Restaurante does not contain proteins nor glucose. Therefore, the victim's last meal was at the Avanti's Restaurant.

The Translucence test.

1. Using a dropper, place few drops of the unknown substance on the tissue paper.
2. Wait for the unknown substance to be dried.
3. When it is dried, look through the spot of the drop. If it became translucent, the unknown substance contains lipids, which allows the light to go through. If the drop didn't make any changes, it does not contain any lipids.

The Biuret Reagent Test
1. Using a dropper, add drops of the Biuret Reagent into a test tube.
2. Using another dropper, add the unknown substance into the same test tube that has Biuret Reagent in it.
3. If the substance changed the color to pink or purple, it indicates that the substance contains protein.

The Glucose Test
1. Using a dropper, add a drop of the Benedicts Reagent into a test tube.
2. Using another dropper, add the unknown substance into the same test tube that has Benedicts Reagent already in it.
3. Place the test tube inside the beaker with a half-full of hot water.
4. If the substance changed the color to yellow, orange, or brown, it indicates that the substance contains the monosaccharide(glucose).

The Iodine Test
1. Using a dropper add a drop of the iodine into a test tube.
2. Using another dropper, add the unknown substance into the same test tube that has iodine in

it.
3. If the substance changed its color to black or blue, it indicates that it contains the polysaccharide(starch).