Hormones and Receptors Flashcards
what are. genomic effects
altered gene expression
what are non genomic effects
altered cell shape or movement, and altered metabolism
what does a lower concentration at KD indicate
higher affinity for binding that hormone
describe how the short loop negative feedback works
hypothalamus produces releasing hormone which acts on anterior pituitary to release a tropic hormone, which then acts back on the hypothalamus to stop the releasing hormone
what are the types of mechanisms of ligand to receptor binding
-contact dependent (juxtacrine)
- paracrine
-synaptic
-endocrine
what happens in contact dependent signaling (juxtacrine)
the signal molecule is on a cell and the receptor is on a target cell and they bind
describe paracrine signaling
a cell releases a ligand to bind with a receptor on another nearby cell
describe synaptic signaling
chemical synapse down an axon to target cell
descirbe endocrine signaling
an endocrine cell releases the hormone into the blood stream to bind a target downstream
describe GPCR second messenger pathway`
adenylate cyclase converts ATP into cAMP. OR PLC is activate which cleaves PIP2 into IP3 and DAG thus releasing Ca2+ ions
describe the primary structure of amino acids
linear sequence of AAs
describe the secondary structure of amino acids
local region of folding of a primary sequence (alpha helix of beta pleated sheet)
describe the tertiary structure of AAs
3D arrangement of polypeptide sequence
describe the quaternary structure of AAs
sum of multiple polypeptide units
what is a protease
an enzyme that cleaves protein substrates into different parts
describe steroid hormones
a mutli ring organic structure which imparts the characteristic of water insolubility on these material
describe polypeptide hormones
water soluble protein hormones like insulin glucagon
what are nuclear receptors responsible for
recognizing and binding to steroid hormones and thyroxine
describe how the long loop feedback works
hypothalamus produces releasing hormone which acts on anterior pituitary to release a tropic hormone, which then acts on an endocrine gland to release a hormone that acts back on the hypothalamus to stop releasing the hormone
describe hydrophilic second messengers with examples
water soluble located in cytoplasm. examples: cGMP, IP3, Ca2+
describe hydrophobic second messengers
water insoluble, membrane associated and diffuse from the plasma membrane and bind to membrane associated effector proteins involved in a variety of signaling cascades
examples: DAG and phosphatidylinositols
describe second messengers that are gases and give examples
diffuse through both cytosol and across cell membranes
ex: NO, CO, and HS
what is mcCune Albright syndrome caused by
a mutation in GNAS which results in a G protein which is always on that activates adenylate cyclase. this leads to an over production of several hormones resulting in abnormal bone growth, unusual skin pigmentation, and endocrine problems
- not inherited
how do genomic actions of hormones affect gene transcription
Nuclear receptor with a bound hormone binds to a response element (a DNA sequence) that activates or suppresses transcription factors such as RNA polymerase
