Question

Which of the following hormones does not contain a polypeptide?
a. Prostaglandin
b. Oxytocin
c. Insulin
d. Antidiuretic hormone

Answer 1

A hormone is a substance that is a member of the class of signaling molecules, this molecule is produced by the glands and in the multicellular organisms, this hormones are transported by the circulatory system, to target the distant organs which regulate the physiology and behavior.

Complete answer:
Generally, hormones define functionally but not structurally, which may have diverse chemical structures. Hormones usually occur in the higher organisms, but in the unicellular organisms, this is called molecular signaling.

Based on the chemical structure they are classified as

Peptide: Hormones that are made up of a chain of amino acids and they are from 3 to 100 some of the examples are oxytocin, insulin, and ADH. The sequence of these amino acids is enclosed in DNA where they can be modified and packed in vesicles and this is soluble in water, and because of this soluble nature, they bind to the receptors on the membrane and can travel through it.

Eicosanoid: Some hormones are derived from lipids, examples include prostaglandins and thromboxane. They are hydrophobic and they act as membrane receptors.

Steroid: These are the hormones that derive from the cholesterol, and examples of these hormones are estrogen and progesterone. Steroids contain four fused rings, and they are lipophilic and they can cross the membrane and bind to the nuclear receptors.

Hence, the correct answer is option (A).

Note: Hormones have so many roles in our body and they affect various things, which include the stimulation or inhibition of growth, and circadian rhythms and mood swings, apoptosis, and they also regulate the metabolism of the reproductive cycle, puberty, etc.