Hormones and receptors

Question 1

1. Distinguish the structure of peptide, steroid and thyroid hormones.

Answer 1

tyrosine derivatives- dop, epi, NE
-hydrophilic
-free hormones (but also degraded quickly, -short t1/2
peptides- hypothalmic hormones
-hydrophilic
-free hormones (but also degraded quickly, short t1/2
proteins- insulinm GH
-hydrophilic
-free hormones (but also degraded quickly, -short t1/2
steroids- estrogen testosterone
-hydrophobic

Question 2

2. Contrast the structures and cellular locations of the peptide and the steroid/thyroid hormones types of receptors.

Answer 2

peptide- GCPR, JAK-STAT, EGF-TYROSINE
-transmembrane
Steroid- intracellular–>transported to nucleus–>SRE’s–>gene transcription

Question 3

3. Identify the mechanisms of signaling of peptide hormones.

Answer 3

GCPR
Gs
Gi
Gq

JAK-STAT- Tyrosine kinase receptors–>janice kinase signal transducers and activators of transcription

EGF-TYROSINE–> EGFR–>Tyrosine kinase dimerize–»

Question 4

4. Compare the mechanisms of action of steroid and thyroid hormones.

Answer 4

1

Question 5

5. Identify different forms of regulation of hormone synthesis and release.

Answer 5

pulsatile release

circadian regulation

feedback regulation

endproduct regulation

receptor down regulTION

spare receptors