What is the chemical nature of insulin hormone?

Step-by-step solution

On the basis of their chemical nature, hormones can be divided into groups : (i) peptide, polypeptide, protein hormones (e.g., insulin, glucagon, pituitary hormones, hypothalamic hormones, etc.) (ii) steroids (e.g., cortisol, testosterone, estradiol and progesterone) (iii) iodothyronines (thyroid hormones) (iv) amino-acid derivatives (e.g., epinephrine) Hormones which interact with membrane-bound receptors normally do not enter the target cell, but generate second messengers (e.g., cyclic AMP, IP3, Ca++ etc) which