# 2.1.0: Prelude to Carbohydrates

Carbohydrates have become surprisingly divisive. Some people swear by them, others swear against them. But it is important to understand that carbohydrates are a diverse group of compounds that have a multitude of effects in the body. Thus, trying to make blanket statements about carbohydrates is probably not a good idea. Carbohydrates are named because they are hydrated (as in water, H2O) carbon. Below is the formula showing how carbon dioxide (CO2) and water (H2O) are used to make carbohydrates (CH2O)n and oxygen (O2). The “n” after the carbohydrate in the formula indicates that the chemical formula is repeated an unknown number of times, but that for every carbon and oxygen, there will always be two hydrogens.

$\ce{CO_2 + H_2O \rightarrow (CH_2O)_n + O_2}$

Carbohydrates are produced by plants through a process known as photosynthesis. In this process, plants use the energy from photons of light to synthesize carbohydrates. The formula for this reaction looks like this:

$\ce{6CO_2 + 6H-2O + \text{Light} \rightarrow C_6H_{12}O_6 + 6O_2}$

There are many different types of carbohydrates as shown in the figure below. The first way that carbohydrates can be divided is into simple, complex, and sugar alcohols. As the names imply, complex carbohydrates contain more sugar units, while simple carbohydrates contain either 1 or 2 sugars. In the next sections, you will learn more about the different forms of carbohydrates.

Figure 2.11 The different forms of carbohydrates