Proteins are of two types based on function.
(i) Structural protein: All the proteins that make up the organism’s body are called structural proteins. E.g. Keratin (skin, hair, horns, nails, scales, feathers), collagen (bones, tendons, connective tissue), keratin (insects), sein (bone), fibrin (silk, spider webs), chondrin (cartilage) ), skerroprotein (insect exoskeleton) etc.
(ii) Functional protein: Those proteins that cause the metabolism of the organism are called functional proteins. These are called regulatory proteins. For example, enzymes, hormones, vitamins, respiratory etc.