It is important in both energy producing pathway and fatty acid metabolism. The vitamin itself does not have the active site. Toxic effects of feeding raw egg white to animals were first observed in 1916. Later, biotin was identified as the missing vitamin that caused the problem. Biotin is a prosthetic group which binds to lysine of the enzyme via peptide bond.
Biotin deficiency causes dermatitis and hair loss.
This is usually caused not by lack of biotin in the diet. Instead, antivitamin, avidin, binds biotin and makes it unavailable for digestion and absorption. Raw egg white contains a lot of avidin. Folic acid is the most prominent human vitamin deficiency. The function of THEA is as transport vehicle for single carbon unit.