Choose the correct option :
1. (a) and (b)
2. (b) and (c)
3. (c) and (d)
4. (a) and (c)
HINT: Insulin and albumin are globular proteins.
Explanation:
STEP 1: Proteins can be classified into two types on the basis of their molecular shape, i.e., fibrous proteins and globular proteins.
Fibrous proteins are made up of polypeptide chains that are elongated and fibrous in nature or have a sheet-like structure. These fibres and sheets are mechanically strong and are water-insoluble. They are often structural proteins that provide strength and protection to cells and tissue.
The structure of the protein which results when the chain of polypeptides coil around to give a spherical shape is known as globular protein. These proteins are soluble in water.
STEP 2: Insulin and albumin are globular proteins.
Examples of fibrous proteins are keratins, collagens, myosins, and elastins. Hair and the outer layer of skin are composed of keratin. Connective tissues contain collagen.
Myosins are muscle proteins and are capable of contraction and extension.
Hence, (a) and (c) are correct choices.
