Reaction catalyzed by Beta-ketoacyl-ACP-synthase. ACP-bound acyl chain (left) is extended by two carbon atoms stemming from malonyl-ACP. R=H during the first cycle and R=C<sub>2n</sub>H<sub>4n+1</sub> during the following cycles of fatty acid synthesis.
<a href="//commons.wikimedia.org/wiki/User:Hbf878" title="User:Hbf878">Hbf878</a>
<span class="int-own-work" lang="en">Own work</span>