And whenever a system in nature contains charge, what that means is its energy is higher, it's less stable and it's more reactive. So essentially bifus formulating a glucose molecule and transforming it into glucose expositate, our cells increase the reactivity of the glucose molecule and that allows it to basically undergo further processes and ultimately break down and form the ATP energy molecules that our cells use as the major energy source. Now, the second reason why we phosphorylate glucose molecules is to increase the polarity of the glucose molecule. So compared to this unmodified glucose, the phosphorylated glucose contains a higher charge and so it is more polar. And because this molecule is more polar, it is much less likely to actually spontaneously leave the cell. Why?