21. Vit H , biotin Flashcards
21. Structure, metabolism, biochemical role and deficiency of biotine (vitamin H). 22. Structure and metabolism of folic acid (vitamin B9).
1
Q
Structure:
A
-
2
Q
Characteristics:
A
Soulbe in alkali and hot water
- stable to air, daylight, heat
- UV destroys it
3
Q
Metabolism:
A
- It is in plant and animal products
- microbial synthesis
- prevented by avidin in egg white, biotin in egg yolk.
- urin: biotin sulfide
- Absorbed intact, it is only side chain which will go through changes. (ox)
4
Q
Biochemical role:
A
- Enzyme (prosthetic group)
- Carrier of active CO2, (ATP is needed) Carboxylations (carboxy biotin) Attach to N.
- Biotin + lysin =biocytin
- It helps when pyruvate goes to oxaloacetate
- It is needed in the FA synthesis, gluconeogenesis and beta ox.
5
Q
Deficiency:
A
-Avidin , connect to biotin, no absorption.
-Rats get dermatitis
-Slow growth, weight loss
- Humans get hair loss
-poultry: dermatitis, feather loss, reduced egg prod, fatty liver, lesions.
Pigs: Dermatitis, loss of hair, ulcers.
