Chitin, homo or heteropolysaccharide?
Even teachers are sometimes wrong. ;)

Chitin is a homopolysaccharide. This just means that it is made up of repeating units of the same monosaccharide - in this case that monosaccharide is N-acetylglucosamine. Other examples of homopolysaccharides are glycogen and cellulose.

The basic structure of chitin is shown below as a polymer of two N-acetylglucosamine units:


Homopolysaccharides can be linear chains or branched, as long as they are made up of just one type of sugar unit. A heteropolysaccharide is made up of multiple different monosaccharide units. Glycosaminoglycans would be an example of a heterpolysaccharide as they contain two different sugar units.