Lipoic acid is a growth factor for many bacteria and protozoa and an essential component...

Lipoic acid is a growth factor for many bacteria and protozoa and an essential component of several enzymes involved in human metabolism.

(a) Name the two functional groups in lipoic acid. (Chapter 1)

(b) During human metabolism, the disulfide bond of lipoic acid is reduced to two thiol groups. Draw a structural formula for this reduced form of lipoic acid.