Carbohydrate metabolism is the process by which the body breaks down carbohydrates from food into glucose, a simple sugar that serves as a primary energy source. This process begins in the mouth with enzymes in saliva and continues in the stomach and small intestine, where carbohydrates are further digested and absorbed into the bloodstream. Once in the bloodstream, glucose can be used immediately for energy or stored in the liver and muscles as glycogen for later use. Hormones like insulin help regulate blood sugar levels, ensuring that cells receive the energy they need while maintaining balance in the body.