Question | Answer |
sensor cell | produces hormones in response to specific stimuli from the external environment |
target cell | has receptor for hormones - hormone binding to the receptor causes the target cell to respond by changing cellular functions |
hormones | intercellular information carriers between sensor cells and target cells - hormones are responsible for coordinating activities of different cells in a multicellular organism |
receptors | proteins that bind hormones with high specificity and affinity |
endocrine hormones | produced by endocrine glands and transported to target cells in the circulatory system |
paracrine hormones | produced by cells that are in close proximity to target cells |
autocrine hormones | produced by cells that are also the target of action |
hydrophillic hormones | bind to receptors on the outer surface of the cell |
lipophilic hormones | bind to intracellular receptors |
g-protein coupled receptor | ligand bound receptor activates heterotrimeric g-protein that regulates the activity of effector proteins in the plasma membrane (typically enz. or ion channels that increase the concentration of second messengers) |
enzyme receptor | extracellular domain binds to polypeptide hormones and cytoplasmic domain with enz. activity |
cytokine receptor | usually composed of 2+ subunits - cytoplasmic domains associate with Jak tyrosine kinases to pass the "message" |
ion-channel receptors | mediate the action of small # of neurotransmitters - NT binding causes transient opening of ion channels |
what is the second messenger for Adenylate cyclase | cAMP |
what is the second messenger for Guanylate cyclase | cGMP |
what is the second messenger for Phospholipase C | Phosphatidylinositol system: DAG + IP3 |
what is the second messenger for Ion Channels | Calcium |
Function of protein kinases | transfer the gamma phosphate group from ATP to the OH of ser, thr, or tyr |
function of protein phosphatases | reverse kinase action by hydrolyzing the phospho residue to the free OH form |
Gs stimulates | Adenylate cyclase, second messenger = cAMP |
Gi inhibits | Adenylate cyclase, second messenger = cAMP |
Gq stimulates | Phospholipase C Beta, second messengers =IP3, DAG, + Ca2+ |
G12 stimulates | ion channels |
SH2 domain binds to | short peptide motifs of proteins with phosphtyrosine |
PTB domains bind to | short peptide motifs of proteins containing phosphotyrosine OR tyrosine |
SH3 domains bind to | proline rich motifs |
PH domains promote | associations with phospholipids of membranes and possibly to integral membrane proteins |
progestins come from | stromal cells of the corpus luteum |
androgens come from | leydig cells of the testis AND reticularis cells of the adrenal cortex |
estrogens come from | theca and granulosa cells of ovary |
glucocorticoids come from | fasciculata cells of the adreal cortex |
mineralocorticoids come from | glomerulosa cells of the adrenal cortex |
Physiological action of Aldosterone | FLUID BALANCE Retention of Na+ and H20, Excretion of K+ and H+, increased vasoconstriction |
Physiological action of Cortisol | STRESS RESPONSE regulation of metabolism to maximize fuel for cells, down regulate immune response |
Physiological action of Androsteinedione + Testosterone | male sex characteristics |
Physiological action of Estrone + Estradiol | female sex characteristics |
Affected steroids and physiological effects of 21alpha-hydroxylase deficiency | decreased cortisol and aldosterone, increased androgens --> increased ACTH, decreased porter-silber reaction, increased zimmerman reaction |
affected steroids and physiological effects of 11beta-hydroxylase deficiency | decreased cortisol, corticosterone, aldosterone, increased 11-deoxycortisol, 11-deoxycorticosterone, androgens --> increased ACTH, increased Na and H20 retention, masculinization, increased porter-silber reaction, increased zimmerman reaction |