Carbohydrates are found in the foods we eat, and they are broken down into glucose in our bodies. When oxygenated blood is transferred to body parts via various blood arteries during respiration. The oxygen in the cells reacts with the glucose, resulting in an exothermic reaction that produces heat, which we exhale out with CO2 as a byproduct or waste. In this way, the glucose is mixed up and sent to all of the cells via circulation.
