1. HOW DO LIPID SOLUBLE HORMONES WORK???

2. 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.

3. 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.

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

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

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

9. Mechanism of Action of Lipid-Soluble Hormones
Process Diagrams Step-by-Step
Copyright © 2007 by John Wiley & Sons, Inc.

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

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

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

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