Lec 5 - Peptides and steroid hormones Flashcards
hormone definition
chemical messenger produced by endocrine gland
that’s released into circulation and transported to a distant organ
what 2 types of molecules do GPCRs respond to
polypeptides
modified amino acids
what hormone is tyrosine a precursor to
tyrosine = dopamine= noradrenaline = adrenaline
what is tryptophan a precursor to
trp = serotonin = melatonin
examples of hormones that are GPCR ligands
vasopressin
GH
parathyroid hormones
examples of recpetor tyrosine kinase ligands
insulin
examples of steroid hormones
cortisol
aldosterone
sex hormones
how is secretion a 2 step process
- Moving vesicle to membrane where vesicles are docked
via disruption of the cytoskelton (e.v. vincrisitine) - Fusing of vesicle to the plasma memb via docking and fusion proteins (SNAP SNARE)
how is peptide hormone release biphasic
when stim hits
1. docked granules will be released
2. non docked granules release slowly (need to be synthesised and transported first)
what can be used to identify GPCR by hydrophobicity
hydropathy plot
what does Protein kinase A do
phosphorylate serine/threonine
and
tyrosine
what does Gq do
modify intracellular Ca levels
which 2 Ca pumps are there
PMCA - plasma memb ca2+ ATPase
Which pumps it out of the cell
Or
SERCA - sarcoplasmic reticulum Ca2+ ATPase = back into stores
2 types of channels that will let in Ca from outside to inside cell
- receptor operated Ca channels (e.g. H1 histamine receptor)
- voltage sensitive Ca channel (in excitable tissues)
cortisol precursor
cholesterol
