Polysaccharides are classified as complex because they are composed of many simple sugars.

Polysaccharides are indeed classified as complex carbohydrates. This is because they are made up of many simple sugar molecules, also known as monosaccharides, linked together in a chain. Here's a step-by-step breakdown:

1. Monosaccharides: These are the simplest form of carbohydrates. Examples include glucose, fructose, and galactose.

2. Disaccharides: These are formed when two monosaccharides are linked together. Examples include sucrose (glucose + fructose) and lactose (glucose + galactose).

3. Polysaccharides: These are complex carbohydrates. They are formed when more than two monosaccharides are linked together. Examples include starch, glycogen, and cellulose.

So, the complexity of polysaccharides comes from the fact that they are made up of many simple sugar molecules.