What is a polysaccharide?

A polysaccharide is defined as a carbohydrate that consists of long chains of monosaccharide units linked together by glycosidic bonds. These chains can be branched or unbranched and can vary greatly in size. Common examples of polysaccharides include starch, glycogen, and cellulose, all of which play crucial roles in energy storage and structural components in living organisms.

In the context of macromolecules, polysaccharides are important because they serve as a primary source of energy and provide structural support in plant cell walls (as in cellulose) or can be storage forms of energy, such as glycogen in animals. The complexity of their structure allows them to perform various biological functions that simpler sugars cannot achieve on their own.

Understanding that polysaccharides are made of multiple monosaccharides distinguishes them from simpler carbohydrates and other macromolecules such as proteins and lipids, each composed of different building blocks and serving different roles within biological systems.