Vitamin C Flashcards
Vitamin C
ascorbic acid
What are the two forms of vitamin C?
-reduced
-oxidized
The reduced and oxidized forms are ________ __________
biologically active
What can the dehydro (oxidized form) further oxidize to?
diketogulonic acid (biologically inactive)
Vitamin C is very susceptible to destruction by ________ which is accelerated by ______
oxidation; heat
What is vitamin C more stable in?
acid more than alkaline medium
What is vitamin C readily destroyed by?
cooking, particularly where the pH is alkaline
What is vitamin C classified as?
an antioxidant
-used in canning of certain fruits to prevent darkening due to oxidative changes
Vitamin C functions in hydroxylation of ______
proline
-hydroxyproline is a constituent of collagen
-collagen is required for the maintenance of intercellular material
What happens to collagen if vitamin C is deficient?
collagen molecule lacks the strength and rigidity which are provided by the hydroxyl groups
What biochemical reaction needs vitamin C?
tyrosine metabolism
Rebound scurvy
a condition that can develop where ascorbic acid oxidase increases to remove excess ascorbate
Types of vitamin C assays
-chemical
-biological
-bioassay and simple curative method
Who is vitamin C is a dietary essential for:
-human
-monkey
-indian fruit bat
-primates
-guinea pig
-certain fish
Deficiency symptoms of vitamin C
-swollen, bleeding, and ulcerated gums
-loosening of teeth
-weak bones
-fragility of capillaries resulting in hemorrhages throughout the body
-wounds of scorbutic animals fail to heal
-scurvy
-failure of dentine and enamel formation in teeth
-rupture of capillaries of the skin and mucous membranes
