Scurvy is d ue to deficiency of -

Ans. is 'a' i.e., Vitamin Co Scurvy is due to vitamin C deficiency,Antioxidant mechanismsCells have multiple mechanisms to remove free radicals and there by minimize injury. There are several nonenzymatic and enzymatic systems that contribute to inactivation of free radical reactions.A. Non-enzymatic systemo Antioxidants (Vit 'E', Vit A, Vit C, glutathione and Cysteine) block the initiation of free radical formation and inactivate free radicals.o Tissue proteins (transferrin, ferritin, lactoferrin, and ceruloplasmin). Iron and copper can catalyze the formation of free radicals, these transport and storage proteins decrease the reactive free iron and copper, thereby minimizing the free radical formation.B. Enzymatic systemo A series of enzymes acts as free radical-scavenging systems and breakdown hydrogen peroxide and superoxide anion.1. Catalaseo Present in peroxisomes and decomposes H,0,2. Superoxide desmutase (SOD)o Manganese - superoxide dismutase is present in mitochondria, while copper-zinc-superoxide dismutase is found in the cytosol,o It converts superoxide to H,G,3. Glutathione peroxidaseo Present in mitochondria & cytosol.o It catalyzes free radical breaksown.H2O2+2GSH-GSSG + 2H2O2OH+2GSH-GSSG + 2H2Oo Intracellular ratio of oxidized glutathione (G S S G) to reduced glutathione (G S M) is a reflection of the oxidative state of the cell.