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Question
How are proteins classified on the basis of molecular shapes?
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Solution
On the basis of molecular shape, proteins are classified into two types—fibrous proteins and globular proteins.
- Fibrous proteins:- They are insoluble in water, long, thread-like and tend to lie side by side to form fibres. The polypeptide chains are held together by hydrogen bonds. Examples: Collagen in tendons; keratin in hair, skin, nails, horn and feathers; myosin in muscle; fibroin in silk
- Globular proteins:- They are soluble in water and aqueous solutions of bases, acids and salts. They are folded to form a spherical shape, have intramolecular hydrogen bonding and have weak intermolecular forces as compared to fibrous proteins.
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