Final answer:
The pectins and hemicellulose found in plant cell walls are synthesized in the Golgi apparatus.
Step-by-step explanation:
The pectins and hemicellulose found in plant cell walls are synthesized in the Golgi apparatus. In plant cells, the Golgi apparatus has the additional role of synthesizing polysaccharides, some of which are incorporated into the cell wall and some of which are used in other parts of the cell.