Question

Many choice: Hormone receptors may alter

Select one or more:

a. Gene expression

b. The activity of ion channels

c. The rate of ATP synthesis in mitochondria

Answer 1

Answer:

All of the above;

Option A (Gene expression)

Option B (The activity of ion channels)

Option C (The rate of ATP synthesis in mitochondria)

Explanation: Hormones are the non nutrient chemicals which bring about the different physiological activities of our body. Depending on their solubility, hormones are of two types;

Fat soluble and water soluble

Fat soluble hormones are soluble in fats and their examples include the steroid hormones and the thyroid hormone

Whereas the water soluble hormones are soluble in water. Example is the Growth hormone

A hormone always gets bound to its specific receptor in order to mediate its action and on the basis of the nature of the hormones; receptors are of two types;

a) Intracellular receptor: These receptors are located inside the nucleus as the hormones are soluble in lipids. Since the cell membrane also is made of lipid; these hormones gets an easy entry and directly enter into the nucleus of the cell wherein they modify the DNA of the nucleus of the cell and likewise also brings about the changes in the gene expression of a cell

b) Extracellular receptors: these are the receptors which remains located at the surface of the cell. These receptors are present for the class of hormones which are water soluble in nature. They cannot cross the cell membrane of the cell and likewise their receptors are located at the surface of the cell. In order to mediate the hormone’s action, they alter and facilitate the recruitment of many ion channels like calcium ions and IP3. Thus, extracellular hormone receptors are known to alter the activity of the ion channels.

Furthermore, the thyroid hormone released from the thyroid gland namely the triiodothyronine (T3) is known to exert its function by regulating the ATP synthesis in the mitochondria. Thyroid hormones are lipid soluble in nature. They thus cross the cell’s membrane and enter into the mitochondria and are thus known to have modified its activity by altering the rate of ATP synthesis by them.