Question

outline the difference in the moles of actions of lipid soluble hormone versus water soluble hormones

Answer 1

The modes of action of lipid soluble hormone differ from that of water soluble hormones. Water soluble hormones are hydrophilic and affect target cells by binding to their surface receptors while lipid soluble hormones affect cells by binding to receptors inside the target cells and are hydrophilic.

Mode of action of water soluble hormone-A water hormone diffuses from the blood and as the first messenger the hormone binds to its receptor on the extracellular surface of the plasma membrane thus activating many G-proteins which in turn activates adenylate cyclase. Adenylate cyclase converts ATP into cyclic-AMP in the cytosol. Cyclic-AMP as the second messenger activates one or more protein kinases which phosphorylate one or more cellular proteins switching them off oe on as a result of which physiological responses are generated.

Mode of action of lipid-soluble hormones includes diffusion into the blood, through interstitial fluid and through the lipid bilayer where it binds to the intracellular receptors and activates it. This activated complex of receptor and hormone then binds to specific genes on DNA and alter the gene expression. Activation of these genes initiates transcription of mRNA ain the nucleus. The mRNA then enters the cytosol and binds to a ribosome. mRNA gets translated to tRNA to form an amino acid(protein) which alter the cells’ activity