<span>The nitrogenous base pairs, which are linked by hydrogen bonds that also hold the strands together, are between this backbone. However, the nitrogenous bases, which are adenine, thymine, cytosine and guanine, pair up so that cytosine only pairs with guanine and adenine links up with thymine.</span>
The purpose of the digestive system is to break down food into simple molecules that the cells of the body can use.
Food is broken down into its simplest units called monomers. Proteins are broken down into amino acids, fats are broken down into fatty acids and glycerol while carbohydrates are broken down into glucose units.
Glucose is taken in by the cells of the body and through the process of cellular respiration is used to produce the ATP, the form of energy that cells use. Cellular respiration is the process by which cells use glucose to produce energy to power their functions.
ATP, also called adenosine triphosphate or the body's energy currency, is a compound that is synthesized when we have a compound called adenosine diphosphate (ADP). When this compound gets another phosphate group (P) attached, we get the more known ATP. This is also why the name changes from diphosphate to triphosphate (di - two, tri - three).
