Exam 3 Ch 11 Flashcards
polypeptide hormones are …
less than 100 amino acids
proteins are …
over 100 amino acids
True or false, hormones are modified from each other
true
Preprohormone
newly synthesized from mRNA, inactive
what part of the preprohormone gets cut out so that the hormone can be active?
the signal sequence and the connecting polypeptide
Prohormone
modified by rough ER
Prehormone
inactive until chemically modified in target cell
Hydrophilic hormones
monoamines, peptides, glycoproteins
hydrophobic hormones
steroids, thyroid hormones, melatonin,
by what method are hydrophilic messengers secreted by the endocrine cell into the blood vessel?
exocytosis. Hydrophobic is through diffusion
What do extraceullular receptors do?
bind hydrophilic hormones that cannot cross the plasma membrane
use a second-messenger
What do intracellular receptors do?
- Bind hydrophobic
hormones that can cross
the plasma membrane - Translocate to the nucleus
How do you up-regulate to increase hormone response?
increase the number of receptors. Down-regulation reduces it
Mech for steroid hormone action
carrier protein brings hormone, binds to receptor protein, other domain of receptor protein binds to DNA.
true or false, steroid hormones are homodimers
true
What’s the area of the DNA that the steroid hormone receptors bind to
hormone response element. the target gene is right next to it
During the thyroid hormone action mechanism, when is the hormone T4?
before it binds the binding protein in the cell
What happens in a hydrophilic hormone mechanisms
Second messengers are involved in the
What is phospholipase C?
second messenger?
Where does the signal go after the receptor protein and phospholipase C?
Into the endoplasmic reticulum
Is insulin receptor able to bind with just one receptor?
No, it’s a dimer receptor
What does insulin bind cause?
autophosphorylation of receptor , causes cascade of effects
Where are hormones taken up and degraded?
liver and kidneys
What do granulosa cells secret?
Estrogen
