Figure 5211 Page 114

1
Figure 5-21(1)Page 114
Signal molecule
Extracellular fluid
G protein
Receptor
Adenylyl cyclase
Plasma membrane
Cytosol
GDP
Signal molecule
Extracellular fluid
G protein
Receptor
Adenylyl cyclase
Plasma membrane
Cytosol
GDP
2
Figure 5-21(2)Page 114
Adenylyl cyclase activated
Signal molecule
Extracellular fluid
G protein
Receptor
GDP
Second messenger
Cytosol
cAMP
ATP
Cytosol
cAMP
Protein kinase 1
Protein kinase 2
Protein kinase 3
Phoshorylated proteins
Metabolic and structural changes
3
Figure 47-1Page 915
Some Types of Cell Signaling
Endocrine cell
Transported inblood
Classicalendocrine signaling
Response
Hormone
Target cell
Neuroendocrinecell
Transported inblood
Neuroendocrinesignaling
Response
Target cell
Neurohormone
Cell X
Diffusesthroughinterstitialfluid
Autocrineregulation
Response
Hormone
Cell X Target cell
Cell X
Diffuses throughinterstitial fluid
Paracrineregulation
Response
Hormone
Cell Y Target cell
Some types of endocrine signaling
4
Fig. 47-2a,bPage 917
Major chemical groups of hormones
Estradiol(principal estrogen)
Molting hormone(ecdysone)
Cortisol
Steroid hormones
5
Fig. 47-2c,dPage 917
Major chemical groups of hormones (continued)
Norepinephrine
Epinephrine
Thyroxine (T4)
Thyroidhormones
Oxytocin
ADH
Triiodothyronine (T3)
Amino acid derivatives
Peptide hormones
6
Figure 47-3Page 918
Regulation by negative feedback
Ca2 level exceeds normalrange inhibits
parathyroid glands
Very high
Secrete less parathyroid hormone
Less Ca2 released into the blood
Normalrange
HOMEOSTATIC RANGE
Calcium level
More Ca2 released into the blood
Secrete more parathyroid hormone
Ca2 concentration in the bloodbelow normal
range stimulates parathyroid glands
Very low
Time
7
Figure 47-4Page 919
Mechanism of action of steroid hormones
Target cell
Blood vessel
?
?
?
Receptor
Hormones
?
Cells of an endocrine gland
Nucleus
DNA
?
Transcription
mRNA
?
Translationsynthesisof specificproteins
?
Cell activityis altered
8
Figure 47-5Page 919
Overview of peptide hormone action
Hormone
Extracellular fluid(outside cell)
Plasmamembrane
?
Receptor
?
Secondmessengers
?
After activity within the cell
Cytosol
9
Figure 47-6Page 919
Mechanism of action of hormones that use G
proteinlinked receptors and second messengers
Hormone
Extracellular fluid
?
?
Adenylyl cyclaseactivated
Plasmamembrane
?
G protein
?
Receptor
ATP
GTP
cAMP
?
Protein kinase A
Protein kinase A
Protein kinase A
Phosphorylatesproteins
?
?
Affectsmetabolism
Alters membranepermeability
Affectsgene activity
Cytosol