Final answer:
Carbohydrates are a classification of organic compounds that serve as a major source of energy for living organisms.
Step-by-step explanation:
In biology, carbohydrates are a classification of organic compounds that serve as a major source of energy for living organisms. They are made up of carbon, hydrogen, and oxygen atoms, and have a ratio of 1:2:1. Carbohydrates can be found in foods such as bread, pasta, potatoes, grains, fruits, and sugars.