Question

Identify ‘a’ in the given figure.

• A. Target
• B. Receptor
• C. Hormone receptor complex
• D. Second messenger

Answer 1

The correct option is B Receptor

Hormones bind to certain proteins called hormone receptors, which are present on the cell membrane of the target cells or inside the target cells. Binding of a hormone to its receptor results in the formation of a hormone-receptor complex.

Water-soluble hormones, which include amino-acid derivatives, peptides, polypeptides and proteins, interact with membrane-bound receptors, which cannot cross the cell membrane and therefore cannot enter the cell. To produce their effect, they generate second messengers (e.g., cyclic AMP, $I{P}_3$, $C{a}^{++}$ etc.) inside the cell, which in turn regulate cellular metabolism.