Sugar is everywhere in our world, from packaged foods in our diet, like tomato sauce, to homemade baked goods, like pies. In fact, sugar is even the main molecule in fruits and vegetables. The simplest form of sugar is called glucose. Glucose is getting a bad rap lately and many people are cutting sugar out from their diet entirely. However, glucose is the main molecule our bodies use for energy and we cannot survive without it. The process of using glucose to make energy is called cellular respiration.

The reactants, or what we start with, in cellular respiration are glucose and oxygen. We get oxygen from breathing in air. Our bodies do cellular respiration to make energy, which is stored as ATP, and carbon dioxide. Carbon dioxide is a waste product, meaning our bodies don’t want it, so we get rid of it through exhaling.

To start the process of cellular respiration, we need to get glucose into our cells. The first step is to eat a carbohydrate-rich food, made of glucose. Let’s say we eat a cookie. That cookie travels through our digestive system, where it is broken down and absorbed into the blood. The glucose then travels to our cells, where it is let inside. Once inside, the cells use various enzymes, or small proteins that speed up chemical reactions, to change glucose into different molecules. The goal of this process is to release the energy stored in the bonds of atoms that make up glucose.