HOW DO LIPID SOLUBLE HORMONES WORK Step 1

HOW DO LIPID SOLUBLE HORMONES WORK? ? ?

Step 1 • A free lipid-soluble hormone will diffuse out of the blood • The hormone passes through interstitial fluid • Finally the hormone passes through the lipid bi-layer of the cell membrane and moves on into the cell.

Step 2 • If the cell is a target cell, the hormone will bind to and activate its receptors • The hormone will then alter gene expression and will turn specific sections of the DNA on or off.

Step 3 • DNA is transcribed according to the new needs of the cell • m. RNA forms and copies the DNA code • m. RNA will carry the anti-codon to the cytosol

Step 4 • In the cytosol the m. RNA directs the synthesis of new proteins • All synthesis is done on the ribosomes • All processes are controlled by enzymes

Step 5 • The new proteins produced will alter cellular activities based upon the directions of the hormone

Mechanism of Action of Lipid. Soluble Hormones Process Diagrams Step-by-Step Copyright © 2007 by

Free hormone Transport protein Blood capillary 1 Lipid-soluble hormone diffuses into cell Target cell

Free hormone Transport protein Blood capillary 1 Lipid-soluble hormone diffuses into cell 2 Activated Nucleus Receptor receptor-hormone complex alters gene expression DNA Cytosol m. RNA Target cell

Free hormone Transport protein Blood capillary 1 Lipid-soluble hormone diffuses into cell 2 Activated Nucleus Receptor receptor-hormone complex alters gene expression DNA Cytosol m. RNA 3 Newly formed m. RNA directs synthesis of specific proteins on ribosomes Ribosome Target cell

Free hormone Transport protein Blood capillary 1 Lipid-soluble hormone diffuses into cell 2 Activated Nucleus Receptor receptor-hormone complex alters gene expression DNA Cytosol m. RNA 3 Newly formed m. RNA directs synthesis of specific proteins on ribosomes Ribosome New protein 4 New proteins alter cell's activity Target cell