Biotin/Vitamin B7 Flashcards
Biotin Structure, Digestion & Absorption
* 2 rings + _____ acid side chain
* Used to be called Vitamin _
* Often bound to protein in foods – freed by
________ & ________ _______
* Absorbed throughout the _____ Intestine
- valeric
- H
- intestinal & pancreatic enzymes
- Small
Biotin Functions
* Coenzyme for multiple carboxylase enzymes
(enzymes that catalyze carboxylation or
decarboxylation reactions)
* Carboxylic acid = -COOH group
Actions of enzymes requiring biotin:
* Form components of _____ _____ (oxaloacetate & acetyl
CoA)
*______ ____ synthesis
* Catabolise odd chain _____ _____
* Catabolise _____
- carboxylase
- TCA cycle
- Fatty acid
- fatty acids
- leucine
Biotin Deficiency
* Deficiency of biotin alone is _____ EXCEPT
* Is induced when large amounts of
_________ _____ _____ are consumed
* The protein _____ in raw egg white binds
biotin preventing ________
* Thereby impairs lipid and energy
metabolism
- Lethargy, paraesthesia in extremities, hypotonia, depression, hallucinations, red dermatitis. Anorexia, nausea, hair loss, brittle nails, muscle pain
- Fatal if untreated
- rare
- uncooked egg white
- avidin, absorption
Biotin Food Sources
* Almost every food contains biotin
* ____,____ & _____ particularly good sources
* Also produced by bacteria in the intestine
(uncertain absorption)
- Nuts, Eggs and Bran
- bacteria