Chapter 6 Flashcards
1
Q
cyclic AMP second messenger pathway
A
- binging of extra-cellular messsenger to receptor activates a G protein, the alpha subunit of which shuttles to and activates adenylyl cyclase
- adenyly cyclase converts ATp to cAMP
- cAMP activates kinase A
- protein kinase A phosphorylates inactivate traget protein, activationing it
- active target protein brings about desired response
2
Q
uses of cAMP
A
- modification of heart rate
- formation of female sex hormones in ovaries
- breakdown of glycogen to glucose in the liver
- urine formation in the kidneys
3
Q
hydrophilic hormones
A
- bind to surface receptors
- highly water soluable
- can alter cells premaritally
uses: - cyclic AMP second messenger pathway
- calcium second messenger pathway
4
Q
Calcium second messenger system
A
- binging of extracellular messenger to receptor activates a G protein, the alpha subunit of which shuttles to and activates phospholipase C
- phospholipase C converts PIP to Ip and DAG
3a. IP mobilizes intracellular CA
4a. ca activates calmodulin
5a. ca- calmodulin complex activates ca- calmodulin- dependent protein kinase (CaM kinase)
6a. CaM kinase phosphorylase inactivates target protein, activating it.
7a. active target protein brings about disired response
4b. protein kinase C phosphorylastes inactive target protein, activating it.
5b. active target protein brings about desired response.
5
Q
types of hydrophilic hormones
A
- peptide
- catecholamines
6
Q
peptide hormones
A
- amino acid arranged in a chain
Example: insulin
7
Q
Catecholamine
A
- secreted by the adreanal medulla
8
Q
lipophilic hormones
A
- lipid loving hormones
- poor water solubility
- creates new enzymes or protein synthesis
Types: - thyrod
- steriods
9
Q
thyroid hormones
A
secreted by the tyroid hormone
10
Q
steriod hormones
A
- deprived form cortosol
- secreted by the adrensl cortex
Example: Sex hormones (testosterone/estrogen)
11
Q
hydrophilic hormones circulate
A
50% free in blood50% bound to plasma proteins
12
Q
lipophilic hormones circulate
A
100% bound to plasma proteins
13
Q
receptors of lipophic hormones are found
A
on the DNA of the cell
14
Q
receptors of hydrophilic hormones are found on
A
plasma protiens
15
Q
protein synthesis steps
A
- free lymphatic hormones diffuse through the plasma membrane of target cells and binds with receptor cells either in the cytoplasm of the nucelus
- receptors: hormone binding region and DNA binding spot
- binging of hormone receptor complex withDNA turns on specific gene within the cell; gene contains a code for synthesing a given protein; code is transcribed into a complementry messsenger RNA
- new messenger RNA leave nucleus and enter the cytoplasm
- new messenger RNA binds into a ribosome –. “workbench” that mediates the assembly of new proteins
- new protein (enzymal or structural ) produces target cells ultimate physiological response
