<prompt> The enzyme 9 desaturase catalyzes the conversion of stearic acid into?Linolenic acidLinoleic acidOleic acidAll of the above  <response>: The enzyme 9 desaturase, in endoplasmic reticulum, catalyzes conversion of stearic acid to oleic acid, which is a MUFA. 9 desaturase is a mixed-function oxidase, requiring NADPH and O2. Humans cannot introduce double bonds beyond 9 position between C10 and terminal methyl group. Hence, linoleic D9,12 and linolenic acid D 9,12,15 are considered essential fatty acids. Reference: Harpers Illustrated Biochemistry 30th Edition Pg 239 