# What are carbohydrates?

A single unit or monomer of a carbohydrates is called a monosaccharide. These are often ring-shaped and include molecules like glucose and fructose. Also, they tend to have the formula ${C}_{n} {H}_{2} n {O}_{n}$ (so they have twice as many hydrogens as they do carbons and oxygens. Glucose's formula is ${C}_{6} {H}_{12} {O}_{6}$). Here's a picture of glucose: