Which one of the following pairs of chemical substances is correctly categorized?

Options

(a) Calcitonin and thymosin – Thyroid hormones
(b) Pepsin and prolactin – Two digestive enzymes secreted in stomach
(c) Troponin and myosin – Complex proteins in striated muscles
(d) Secretin and rhodopsin – Polypeptide hormones

Correct Answer:

Troponin and myosin – Complex proteins in striated muscles

Explanation:

Troponin is a protein which is found an actin filament and myosin protein is found in myosin filament. Both actin and myosin are complex proteins in striated muscles. Thymosin is a hormone secreted by the thymus that stimulates development of T cells. Prolactin is a hormone released by the pituitary gland that stimulates breast development and milk production in women. Rhodopsin, also known as visual purple, is not a hormone. It is a biological pigment in photoreceptor cells of the retina that is responsible for the first events in the perception of light.