What are carbohydrates mainly used for in organisms?

Carbohydrates play a crucial role in organisms primarily as a source of energy. They are categorized into simple carbohydrates (sugars) and complex carbohydrates (starches and fibers), both of which are metabolized to release energy. This energy can be used immediately by cells for various functions, such as muscle contraction and cellular metabolism.

Additionally, carbohydrates serve a secondary function in energy storage. For example, excess glucose can be converted into glycogen, which is stored in the liver and muscles for later use when energy demands increase. This dual role of providing both immediate energy and serving as an energy reserve distinguishes carbohydrates from other macromolecules, highlighting their significance in biological processes.

While other options may hint at roles that different biological molecules serve, carbohydrates are specifically identified for their immediate energy supply and their function in energy storage, making them essential for maintaining overall metabolic activities in living organisms.