Question:
With the help of a suitable example, write the mechanism of hormone action through membrane receptors.
Answer:
(1) Hormones bind to hormone receptors and then
Affects target cells. Hormone receptors can be cells
May be a membrane or intracellular region.
(2) Lipid-soluble hormones cannot penetrate
Target cells through the plasma membrane, e.g. Peptides and polypeptides
hormones
(3) Hormones interact with and activate surface receptors
metabolic activity. The hormone-receptor complex releases adenylate
cyclase from the receptor site. Cyclic AMP is produced from this enzyme
ATP is present in the cell.
(4) cAMP activates enzymatic activity. A hormone is the first messenger,
So CAMP is the second messenger. Ca++ and cGMP or IP3 (Inositol
triphosphatases) are also second messengers.
(5) These create biochemical processes that occur later
physical process.
