24 extra shit Flashcards
Glutathione
Sulfhydryl Buffer and antioxidant that Protects us from Reactive Oxygen Species (ROS)
-detoxifies hydrogen peroxide (H2O2) by reducing to H2O
Glutathione-Tripeptide w/sulfhydryl-ECG -Glutamate Loses H and attaches to Cysteins Amino group GSH->GSSG Glutathione Reductase -uses NADPH to reduce GSSG to GSH -Contains FAD as prosthetic group
Glutathione Peroxidase
-reduces H2O2 to H20 as GSH is oxidized to GSSG
Selenium (Se) replaces sulfur in R group of active site in Cysteine
-the E-Se (Selenolate) reduces Peroxide to Hydroxyl while being oxidized to an said E-Se-OH (Selenenic Acid)
-E-Se-OH is then reduced by Glutathione which is oxidized
-Oxidized glutathione is reduced by NADPH to NADP+ =GSH
Nitric Oxide
Nitric Oxide (NO)
Second Messenger in signal transducttion pathways
-synthesized from Arginine
Nitrix Oxide Synthase
- synthesized Nitric oxide from Arg, O2, and NADPH
1) Arginine + O2 reduced to N-w-hydroxyarginine +H2O via NADPH to NADP+
2) N-w-hydroxyarginine +O2 is oxidized to Citrulline + H2O via NADP+ to NADPH to form Nitric OXIDE (NO)
Prophyrins
cyclic compounds that readily bind metal ions
Where does Heme Synthesis Occur?
Cellular Localization
- Mitochondria
- Cytoplasm
Organ Localizatoin
- Liver=variable rate
- Erythrocyte producing cells of bone marrow-constant rate
Degradation of Heme
1) Heme + 2O2 +NADPH -> Biliverdin + CO+ 2H2O +NADP+
- loses Fe
2) Biliverdin reduced to Bilirubin
- Biliverdine reductase
- NADPH to NADP+