What is the mechanism of ascorbic acid?
Vitamin C (ascorbic acid) dissociates at physiological pH to form ascorbate, the redox state of the vitamin which is found most abundantly in cells [1]. It is well known that ascorbate acts physiologically as a reductant and enzyme cofactor.
Is ascorbate a reducing agent?
Ascorbate is an excellent reducing agent and readily undergoes two consecutive, one-electron oxidations to form ascorbate radical (Asc•−) and dehydroascorbic acid (DHA).
What is enzyme ascorbic acid oxidase?
copper-containing enzymes; examples are (1) ascorbic acid oxidase (an oxidase is an oxidizing enzyme), which contains eight atoms of copper per molecule; it is widely distributed in plants and microorganisms; (2) cytochrome oxidase, which contains heme and copper in a 1:1 ratio; (3) tyrosinases, which catalyze the …
Where is ascorbate oxidase found?
apoplast
Ascorbate and ascorbate oxidase (AO) (the enzyme that oxidizes ascorbic acid) are found in apoplast and have a strong connection between cell metabolism and cell expansion (Smirnoff, 1996).
Does ascorbic acid increase pH?
Ascorbic acid is known to have an adverse effect by decreasing the gastric pH in patients with gastrointestinal disorders [34].
What functional groups are in vitamin C?
So, thus from the structure of Vitamin C we can see that the functional groups present in it are:- -OH group (i.e. hydroxyl group), -C=O. (carbonyl group) and -O- group (i.e. ether group). Hence, the functional group in vitamin C are hydroxyl, carbonyl and ether respectively.
How does vitamin C act as an antioxidant?
As an antioxidant, vitamin C provides protection against oxidative stress-induced cellular damage by scavenging of reactive oxygen species, vitamin E-dependent neutralization of lipid hydroperoxyl radicals, and by protecting proteins from alkylation by electrophilic lipid peroxidation products.
What is the function of ascorbate oxidase?
Function. This enzyme belongs to the family of oxidoreductases, specifically those acting on diphenols and related substances as donor with oxygen as acceptor. This enzyme participates in ascorbate metabolism. It employs one cofactor, copper.
What does ascorbate oxidase do?
Ascorbate oxidase is a copper-containing enzyme found in melons, seeds, cereals, and fruits and vegetables. It can oxidize ascorbic acid to produce water and dehydroascorbic acid. Compared with non-enzymatic oxidation, ascorbic acid oxidase acts to generate water, while the former generates hydrogen peroxide.