The chemicals (atoms) that join together to make us work, first come together as molecules. (one or more atoms) However, before we can discuss putting molecules together to form DNA, two additional chemicals need to be presented. They are phosphorus and sulfur.
Phosphorus is more abundant than nitrogen. Phosphorus compounds (molecules) are essential constituents of all animal and plant life. When it combines with oxygen it becomes one of the main units in helping to form DNA, which is certainly one of the most complex organic molecules. Its other function is to provide a means for storing energy in the cells. Without phosphorus, none of the ovens (mitochrondia) would work!
Sulfur is the least common chemical. It is used by the human body to help make certain molecules called proteins. Proteins are the building blocks of DNA. Sulfur is also important in forming molecules that help in the cytoplasm to help make the cell work properly.
Wow. There you have it. The building of DNA is ready. Let's see now, oxygen is the chemical extrovert, it wants to bind with everything. Nitrogen is the chemical introvert and can form triple bonds, holding everything inside. Carbon is the strong man who makes things firm. Hydrogen is the minnow, darting about between atoms, easy to make new friends. Phosphorus provides the energy. Sulfur shows up when needed. Sounds like a superhero comic book.