In enzymology, a beta-ketoacyl-acyl-carrier-protein synthase I is an enzyme that catalyzes the chemical reaction an acyl-acyl-carrier-protein + malonyl-acyl-carrier-protein ⇌ {\displaystyle \rightleftharpoons } a 3-oxoacyl-acyl-carrier-protein + CO2 + acyl-carrier-proteinThus, the two substrates of this enzyme are acyl-acyl-carrier-protein and malonyl-acyl-carrier-protein, whereas its 3 products are 3-oxoacyl-acyl-carrier-protein, CO2, and acyl carrier protein. Wikipedia