Furci Final Flashcards
3 main precursors of cholesterol are:
corticosteroids, androgens, estrogens
compared to peptide hormones, steroid hormones are slower/faster acting? with a longer/shorter halflife?
slower, longer
what type of hormone can cross the cell membrane?
lipid soluble
what type of hormones are first messengers?
polypeptide hormones
what is a first messenger?
polypeptide hormones that bind to external receptors causing a cascade of events within the cell
what are second messengers?
they cause the effects within the cell. Examples include low molecular weight molecules lilke cAMP.
the relative size of G-protein coupled receptors is?
Very Large
what is the second messenger responsible for calcium mobilization
PIP2
what hydrolyzes PIP2? What are the products?
PLC hydrolyzes PIP2 into IP3 and DAG
what are the functions of IP3 and DAG (products of PIP2 hydrolysis)
IP3 - water soluble, mobilizes calcium
DAG - hydrophobic, activates PKC family
what type of endocytosis involves clathrin?
receptor mediated endocytosis
what is clathrin
forms a polyhedral lattice (made of 3 light chains and 3 heavy chains) on receptor vesicles in receptor mediated endocytosis
What are the 4 types of receptor, and an example of each?
- G-protein coupled - epinephrine, glucagon, serotonin
- ion-channel - acetylcholine
- tyrosine-kinase linked - erythropoeitin, interferons
- intrinsic enzymatic activity - growth factors, insulin
(4 is similar to 3 - both dimerize)
Cox1 vs Cox2
both stimulate inflammation.
anti-inflammatory meds (NSAIDs) inhibit Cox1, not Cox2
aspirin inactivates both
Cox2 selective inhibitors are effective in conditions like rheumatoid arthritis
how is iron tranported into the cell
carried by transferrin, which is taken up by receptor mediated endocytosis. iron is released in the endosome, and transferrin returns to membrane
