What type of carbohydrate is chitin classified as?

Chitin is classified as a polysaccharide because it is a long-chain polymer made up of repeating units of N-acetylglucosamine, a derivative of glucose. Polysaccharides are complex carbohydrates that consist of many monosaccharide units linked together by glycosidic bonds. In this case, chitin serves various structural functions in the cell walls of fungi and the exoskeletons of arthropods, demonstrating the typical characteristics of polysaccharides, such as being large molecules that can provide structural support and energy storage.

Other classifications mentioned in the options refer to simpler carbohydrates; monosaccharides consist of single sugar molecules, disaccharides consist of two sugar units, and lipids are a different category altogether, primarily related to fats and oils rather than carbohydrates. Thus, identifying chitin as a polysaccharide accurately reflects its structure and role in biology.