(i) Write the structural difference between starch and cellulose.
(ii) What type of linkage is present in Nucleic acids ?
(iii) Give one example each for fibrous protein and globular protein.

Explanation

(i) Starch : It is a mixture of two components-
(a) water soluble component called amylose (15-20%)
(b) and water insoluble component called amylopectin (80-85%)
Both amylose and amylopectins are polymers `alpha-(D)-(+)-` glucose. Amylose contain 200-1000 units whereas amylopectin contain 2000-3000 glucose units.
Cellulose : It consist of 300-3000 glucose units. Cellolose is linear condensation polymer of `beta-D-"Glucose in which "C_(1)` of one glucose is connected to `C_(4)` of the through D-glycosidic linkage.
(ii) Phosphodiester linkage.
(iii) Fibrous protein = kertin
Globular protein = insulin