Antioxidants Flashcards
what are examples of stressors?
aging, wounding, xenobiotics, radiation/light, heat and cold, heavy metals, pollutants, hormones
notable RNS?
nitric oxide, nitrogen dioxide
places where free radicals are made?
mitochondria; vacuoles; nucleus, lysosomes, peroxisomes, ER, cyto, membrane
what is singlet oxygen involved in?
skin, photodamage
what cause production of free radicals?
smoking, strenuous exercise
how is superoxide radical created?
O2 react with catecholamines, semiquinone intermediate in mito, NADPH oxidase in membrane, drug/toxin metabolism (WBCs)
H2O2 is produced by ____
SODs (superoxide dismutases); rxn ascorbate with O2
H2O2 is produced in:
peroxisomes, activated neutrophils, ischemia-reperfusion
this radical is a “severe threat to living systems”, form when exposed to gamma rays and in Haber-Weiss and Fenton rxns
hydroxyl radical
a peripheral e- excited to a higher state, and mroe rxtive than ground state Oxygen
singlet molecular oxygen
how is singlet oxygen formed?
via photochemical rxn, enzymatic rxns (resp bursts), peroxidations
in lipid peroxidation, O2 is slow oxidant in ___ phase, fast oxidant in ___ phase
initiation; propagation
proteins most reactive?
proline, histidine, argenine, cysteine
lipid peroxidation releases rxtive ___
aldehydes
diseases involving oxidative stress
inflammation (arthritis, alzheimer’s, MS, infection), cancer, atherosclerosis, ischemia-reperfusion, aging
ischemia is caused by:
cessation of blood/oxygen supply