TEST FOR PROTEIN

Protein are compound of hydrogen, carbon, oxygen and nitrogen some protein are also contain sulphur or phosphorous. Proteins are longer chain of amino acid.

Approximately twenty amino acid occur naturally, the human body makes ten of this amino acid in the liver, and these are called non essential amino acid. The other ten amino acid must be obtained from the diet; they are called essential amino acid.

Essential amino acids obtained by eating food rich in protein, the food that contain all the essential amino acid are called first class protein. Animal’s protein mostly fall in group. Second class protein lack of one or more essential amino acid, most of the plants fall in this group.

Properties of Protein

1. An amino acid contain an acid carbonyl compound and a basic group, thus amino acid can react with basic or acidic substance

2. Protein has large molecules so they form colloid instead of true solution

3. Protein are denatured by strong heat

4. Protein are affected by pH

Test for protein

Procedure	Observation	Conclusion
Beuret solution i. add small amount of specimen in a clean and dry test tube ii. add equal amount of benedicts solution to the solution then shake	a. violet/purple colour formed b. the solution retained the blue colour of benedicts solution	a. Protein are  present b. protein are absent
Millons solution i.pour 2cm3 of specimen in a test tube ii. add 1cm3 of millon’s solution to the specimen and then boil the mixture	a. Pink coagulating mass b. the solution retained the colour  of millon’s solution	a. Protein are  present b. protein are absent