MCM test 1 Flashcards
scurvy
- defective collagen formation
- vit C deficiency:propyl hydroxylase
- impaired wound healing, capillary hemorhage, deficient platelet, osteoblast, osteoclast function
What does anti-microtubule chemotherapy do?
- inhibits poly/depolymerization
- microtubules stable/nonfunctional=no mitosis
- taxanes, vinca alkaloids, colchcine
how do cells specialize?
expression of receptors
trophic factors
signals that keep cells alive, absence=death
what do responding cells depend on?
position w/n the gradient
what do mitogens do?
activates G1/S-Cdk to stimulate cell division
endocrine
distant sites
paracrine
nearby cells
what signals activate intracellular receptors?
steroids/NO
Where and how do steroids act?
form dimers and act on nuclear receptors, act as transcription factors and change gene expression directly
How is NO made?
NO synthase from arginine
Where and how does NO act?
only locally, acts on guanylyl cyclase which produces cGMP and nitrosylates residues on some proteins
peptide hormones
long half life and distant acting includes GH and neuropeptides
What is the effector mechanism of neurotransmitters?
- ligand-gated ion channels-change ion conc-AP
- G-protein coupled-indirectly regulate ion channels
Eicosanoids
lipids, act locally w/ short half life, induce clotting and inflammation
How are eicosanoids synthesized?
phospholipase A2(phospholipids->arachdonic acid)->COX(arachdonic acid->prostaglandins)
What do NSAIDS and aspirin inhibit?
COX1/2
What are the ligands for ion-channel-coupled receptors?
neurotransmitters
How do GPCR’s bind G proteins?
a binds GTP, By subunits bind the receptor and a subunit
What are the ligands for GPCR’s?
eicosanoids, NT’s, and peptide hormones
What receptors are responsibe for smell, sight, and taste?
GPCR’s
describe the activation of GPCR’s
ligand binds, GDP exchanged for GTP by GEF’s, a subunit dissociates, By subunit dissacociates and then they act on intracellular targets
How are GPCR’s deactivated?
GAP’s hydrolzye GTP to GDP
What are the ligands for Receptor Tyrosine Kinases(RTK’s)?
growth factors and membrane bound ligands
What is special about RTK’s?
have and intrinsically bound tyrosine kinase domain
What are soluble RTK’s associated with the plasma membrane activated by?
TKAR’s (Tyrosine kinase associated receptors)
What do cytokine receptors signal through?
Jak Stat
what ligand activates receptor serine/threonine kinases and what pathway does that activate?
TGF-B, SMAD pathway
What is the ligand for Notch?
delta
what is the ligand for Frizzled?
Wnt
What is the ligand for Patched?
Hedgehog
adenylyl cyclase
forms cAMP from ATP
cAMP phosphodiesterase
degrades cAMP to AMP
What is the action of cAMP?
binds to the regulatory subunit of Protein Kinase A, causing it to dissociate and phosphorylate targets
What is the action of cGMP?
activates protein kinases, ion channels, and phosphodiesterases
