Question

Which one of the following pairs of hormones are the examples of those that can easily pass through the cell membrane of the target cell and bind to the receptor inside it (mostly in the nucleus)?
A. Insulin, glucagon
B. Thyroxine, insulin
C. Somatostatin, oxytocin
D. Cortisol, testosterone

Answer 1

Hint: Lipophilic hormones are easily associated with the bilayer of the plasma membrane and pass through it. So, lipophilic hormones easily pass through the cell membrane of the target cell.

Complete Answer:
- In this particular question, we have found out the cortisol and testosterone are one of the pairs of hormones which can easily pass through the cell membrane of the target cell. These are steroid hormones which are hydrophobic and made up of fats/lipids. Therefore they can easily pass through the cell membrane.
- Steroid hormones such as cortisol and testosterone are derived from cholesterol, which is a major component of the cell membrane. When these types of hormones reach their target cells, they disconnect from transport proteins and pass through the plasma membrane of the cell.
- As it has been mentioned in the question of these hormones, it binds to the receptor mostly in the nucleus of the target cell after across the cell membrane. At first, steroid hormone (cortisol and testosterone) binds to an intracellular receptor protein in the cytoplasm and forms a hormone-receptor complex then this complex is transported into the nucleus.
- Generally, a specific hormone is used to bind with the specific plasma receptor protein—for example, cortisol bound with corticosteroid-binding globulin (CBG) which is present in the blood.
- Moreover, this pair of hormones “cortisol and testosterone” have numerous therapeutic uses as well as regulate a wide range of developmental and physiological activities from fetal life to adulthood. Cortisol and testosterone are examples of those hormones that can easily pass through the cell membrane of the target cell and bind to the receptor inside it (mostly in the nucleus).

So the answer to this question is option D- Cortisol, testosterone.

Note: Hydrophobic hormones can easily pass through the cell membrane of the target cell. Cortisol and testosterone are prominent examples of those types of hormones.