Hope this one might help
Biotin is necessary for cell growth, the production of fatty acids, and the metabolism of fats and amino acids. It plays a role in the citric acid cycle, which is the process by which biochemical energy is generated during aerobic respiration. Biotin not only assists in various metabolic reactions but also helps to transfer carbon dioxide. Biotin may also be helpful in maintaining a steady blood sugar level. Biotin is often recommended for strengthening hair and nails. Consequently, it is found in many cosmetics and health products for the hair and skin, though it cannot be absorbed through the hair or skin itself.
Biotin deficiency is rare, because intestinal bacteria generally produce biotin in excess of the body's daily requirements. For that reason, statutory agencies in many countries, for example the USA and Australia, do not prescribe a recommended daily intake of biotin. However, a number of metabolic disorders exist in which an individual's metabolism of biotin is abnormal; in these disorders, megadoses of biotin, far higher than the average daily intake from food, can generally mitigate symptoms and correct the underlying metabolic disturbance.
How many carbon molecules?
Biotin has the chemical formula C10H16N2O3S1, so it contains 10 carbon atoms, 16 hydrogen atoms, two nitrogen atoms, three oxygen atoms and one sulfur atom for every one molecule of biotin.
These molecules are arranged in a bi-cyclic, or two-ring structure. One ring of biotin contains a ureido, or -N-CO-N- group, and the other ring contains a sulfur atom as part of the tetrahydrothiophene ring.
Biotin has three chiral carbons and can therefore exist in eight different stereoisomer forms; biotin, epibiotin in cis form, allobiotin, and epiallobiotin in trans form, in both D(+) and L(-) forms. Only the D-(+) biotin stereoisomer is physiologically active