Biotin Revision Questions - week 10

Question 1

Food source

Answer 1

• liver, nuts, seeds fish, whole grains

Question 2

Absorption

Answer 2

• found in food as free biotin or byocytin (bound to AA lysine in protein)
• biotinidase unbinds biotin for absorption
• free biotin absorbed by active transport (sodium dependent carrier)
• bioavailabily greate rin eggs and meat sources
• some miinor microbial production in LI
• generally biologically active as biotin

Question 3

Storage

Answer 3

minimally stored in liver, muscles and brain

Question 4

EXcreted

Answer 4

mainly urine, some in bile

Question 5

Coenzyme form

Answer 5

N-carbodylbiotinyl lysine

Question 6

Main function

Answer 6

• cofactor for carboxylase enzymes that participate in FA, AA and energy metabolsim

Question 7

RDI

Answer 7

none

AI - 10ug

Question 8

UL

Answer 8

none

Question 9

Toxicity

Answer 9

unkown

Question 10

Deficiency

Answer 10

is rare

• dermatitis, conjunctivitis, hair loss, NS abnormalities, convulsions
• could be due to genetics (biotinidase enzyme deficiency) or excessive consumption of raw egg white