ppwt 2 Flashcards
what are the caracteristic of large polypetides
- linear chains
- disulfide bridges
- 3d
- water soluble
protein hormone synthesis
- transcription
- translation
- post translational modification
what is the translational modif
- introns need t be splicing out
- poly A tails
- Cap at 5’
what happens in the translation of peptides hormones
- activation of amino acids
- initiation
- elongation
- termination
- protein folding
what needs to be cleaved off in the post-translational modification
the signal sequence
post translational modification
1. pro hormone
2. polyprotein
3. pro hormone
4. separated by alpha and beta subunit
pro hormone : nothing can happen and just be functional or need to cleave one part of the protein
- polyprotein: cleaved in smaller parts (POMC) if it is on the hypothalamus it can be cleaved further and make MSH. If it is in the pituary a small part is retain ACTH
- pro hormone : rearrangement by disulfide bonds therefore the other will not be the same.
- Beta and alpha subunit: bring 2 proteins together by glycosylation
amino acid derived hormones
- thyroid hormones
- adrenal medulla (epinephrine, norepinephrine, dopamine)
storage of hormones
hydrophilic hormones are stored. Cells require a stimulus to activate and release the stored prohormone
how do hydrophilic and hydrophobic hormones circulate in the blood
hydrophilic - free state
hydrophobic - requires a carrier protein that are specific for the particular hromone
what is the function of biding protein
they act as a buffer
hydrophobic vs hydrophilic hormones
hydrophobic :
- steroid and thyronine
- minimal storgae except for thyronine
- have binding protein
- long half life
- receptors : cytoplamic or nuclear
hydrophilic
- peptides nd cathecolamines
- stores after synthesis
- don’t have binding protein
- half life is short
- receptorms in the plasma memebrane
response of a cell to a signal
extracellular signal molecule
bind to the receptor
intracellular signaling proteins
target proteins
the fate of a cell depends on
extracellular signals
response of a cell to a signal
survive
divide
differentiate
die
