Which of the following best describes carbohydrates?

Carbohydrates are best described as the starches and sugars that supply energy. They are essential macromolecules composed of carbon, hydrogen, and oxygen, and play a key role in various biological processes. The primary function of carbohydrates in living organisms is to provide a readily accessible source of energy. Simple carbohydrates, such as glucose, are quickly metabolized to produce ATP, the energy currency of cells. Complex carbohydrates, like starch and glycogen, serve as stored energy reserves that can be broken down when energy is required.

This definition aligns with the overall importance of carbohydrates in nutrition and metabolism, making it clear why this description is accurate for carbohydrates. Their role extends beyond mere energy supply, as they are also important for cellular communication and recognition, contributing to various physiological functions.