As seen in previous lessons, lignocellulosic biomass contains another component, hemicellulose. Rather than being a typical polymer where units repeat over and over again, hemicellulose is a heteropolymer. It has a random, amorphous structure with little strength. It has multiple sugar units rather than the one glucose unit we’ve seen for starch and cellulose, and the average number of sugar units is 500-3000 (glucose units with the starch and cellulose). The monomer units include xylose, mannose, galactose, rhamnose, and arabinose units. The various polymers of hemicellulose include xylan, glucuronoxylan, arabinoxylan, glucomannan, and xyloglucan.