In enzymology, a 24-methylenesterol C-methyltransferase is an enzyme that catalyzes the chemical reaction S-adenosyl-L-methionine + 24-methylenelophenol ⇌ {\displaystyle \rightleftharpoons } S-adenosyl-L-homocysteine + -24-ethylidenelophenolThus, the two substrates of this enzyme are S-adenosyl methionine and 24-methylenelophenol, whereas its two products are S-adenosylhomocysteine and -24-ethylidenelophenol. Wikipedia