(i) Which of the following biomolecules is insoluble in water ? Justify. Insulin, Haemoglobin, Keratin.
(ii) Draw the Haworth structure for `alpha`-D-Glucopyranose.
(iii) Write chemical reaction to show that glucose contains aldehyde as carbonyl group.

Explanation

(i) Bothe insulin and haemoglobin are Globular proteins. These are water soluble the internal hydrogen bonding in the molecules is weak. Keratin is a fibrous protein and is insoluble in water.
(ii) N/A
(iii) Glucose reacts with Tollen's reagent to form a silver mirror. This shows that the carbonyl group present is an aldehydic and not ketonic in nature.