How would you explain the connection between glucose entering the body and energy created by the body to a friend?

I would start off by pointing out that glucose is the main source of energy for our bodies. Glucose is generally obtained through the consumption of carbohydrates. Glucose is stored in our body as glycogen. We then break down this glucose through a series of interrelated processes and cycles. First, we can break a glucose molecule down into two molecules of pyruvate through a series of reactions known as glycolysis. Glycolysis does not require oxygen in order to take place, and along with making two pyruvates, it also produces two ATP molecules (ATP is one of the main energies that our body uses). Then, if oxygen is present, the two pyruvate molecules are oxidized into two Acetyl-CoA molecules. The Acetyl CoA molecules then enter the citric acid cycle where they will eventually go on to produce between 28 and 32 molecules of ATP each. However, if oxygen is not present, then pyruvate cannot be converted into anything, and only two molecules of ATP are made.