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More than __ hormones identified in humans.
Many hormones require __; __ do not
- second messengers
- steroid hormones
Steroid Hormones and Gene Expression
- Pass through target cell membrane and bind to a receptor protein in
- the nucleus.
- - Hormone receptor complex binds to specific sites (acceptor protein) along chromatin to activate gene expression.
- - Two cell types can respond differently to same steroid hormone since acceptor proteins associated with different genes
Peptide Hormones And Hormones Derived From Amino Acids Work By __
What are they?
- Second Messengers:
- Cyclic AMP (cAMP)
- Inositol Triphosphate
- what it stands for?
- what that does
- adenosine 3',5'-cyclic monophosphate
- - synthesized from ATP by adenylate cyclase
- - activates protein kinase A (PKA)
- - PKA phosphorylates target proteins producing cellular response.
- - hydrolyzed/brokendown by phosphodiesterase (PDE)
What is the g-protein pathway if epinephrine initiates the signal?
- Epinephrine binds to G protein- coupled receptor, causing G protein to convert GTP to ATP and also activate adenylyl cyclase.
- Adenylyl cyclase will convert ATP to cAMP, which activatse protein Kinase A and causes a response.
Membrane Lipid System (__)
- IP3 and DAG
- IP3 (inositol triphosphate)
- - DAG (diacylglycerol
What is the cascade, part 1 and 2?
- Phosphatidylinositol (PI): phospholipid present in inner membrane.
- - PI phosphorylated to (2-steps) to phosphatidylinositol-4,5- bisphosphate (PIP2)
What is the cascade, parts 3 and 4?
- PIP2 cleaved by phospholipase C to produce IP3 and DAG (Note: phospholipase C activation is G-protein mediated)
- - IP3 water soluble, diffuses into cytoplasm, binds to receptors on ER stimulates release of Ca2+.
What is the cascade, parts 5 and 6?
- Ca2+ activates calmodulin kinase.
- - DAG activates Protein Kinase C (PKC).