Vitamin B12 - Cobalamin Flashcards
1
Q
forms of cobalamin
A
CO⁺ bound to
- Cl⁻ chloro cobalamin
- OH⁻ hydroxo cobalamin
- CN⁻ cyanocobalamine
2
Q
active form of B12
A
deoxyadenozyl cobalamine
3
Q
storage
A
in the liver
4
Q
transport
A
- active transport from jejunum to liver
- transcobalamin transporters: type II in liver and blood
(type I out from liver)
5
Q
origin of B12
A
only from animals; liver, fermented food/feed: microbes
6
Q
excretion
A
urine
7
Q
biological effecrt:
A
intramolecular rearrangement
8
Q
B12 deficiency in what animals are the most important
A
humans
pig/poultry
ruminant
9
Q
B12 deficiency in humans
A
very sensitive aneamia due to decr. heme synthesis, no absorption of cobalamin leads to:
- slower DNA synthesis
- slower erythrocyte division
10
Q
B12 deficiency in pig/poultry
A
slow growth
impaired feed utilization
milder anemia
11
Q
B12 deficiency in ruminant
A
GNG decreases (succinylCoA (from propionate?))
