Exam - Vitamin C Flashcards
supplement label for Vitamin C
antioxidant support
what is another name for Vit C
ascorbic acid (ascorbate at physiological pH)
which vitamin C isomer is biologically active in humans
L
which animals cannot synthesize vitamin C from glucose (making it essential)
humans
primates
fruit bats
guinea pigs
some birds
why can some animal not synthesize vitamin C from glucose
lack enzyme gulonolactone oxidase
what are the primary sources of vitamin c
fruits and veggies
does vitamin c require digestion prior to absorption
no
how is vitamin c taken up
via sodium-dependent vitamin C 1 and 2 transported in small intestine
what kind of mechanism is responsible for vitamin c uptake
feedback mechanism
what percentage of dietary vitamin C gets absorbed
70-90%
where are vitamin C concentrations high
in white blood cells and many tissues
examples of biological processes that vitamin c is involved in
collagen synthesis
tyrosine synthesis
neurotransmitter synthesis
in biological processes, how does vitamin c act primarily
as a reducing agent (2 electron donor)
how does vitamin C help in hydroxylation reaction in collagen
donates electron to aromatic proline to make Pro-OH so that collagen molecules can stick together
what percentage of the amino acids in pro collagen are prolines
30%, 1/3 are hydroxylated
