Observation

Many candidates attempted this question and their performance was fair. In part (a) many candidates were able to mention nutritional deficiency diseases in humans. In part (b) many candidates could not correctly describe how to test for protein in a food substance.
The expected answers are as follow:

7 (a)         NUTRITIONAL DEFICIENCY DISEASES IN HUMAN

• kwashiorkor
• pellagra
• scurvy
• beriberi
• marasmus
• rickets
• night blindness/xerophthalmia
• goitre
• anaemia

 (b)      TEST FOR PROTEIN IN A FOOD SUBSTANCE
            Biuret Test

• put small quantity of protein in test tube
• add a few drops of water
• add 1 cm3of dilute sodium hydroxide
• add 1% copper III sulphate solution
• shake the solution thoroughly
• a violet/pink colour is observed
• indicating the presence of protein

            Millon’s Test

• put small quantity of protein in test tube
• add a few drops of water
• add millon’s reagent
• heat the mixture
• a reddish brown colour is observed
• indicating the presence of protein

Coagulation Test

• put small quantity of protein in a boiling tube
• add a few drops of water
• heat the solution/mixture
• protein coagulates
• indicating the presence of protein