The dot and cross diagram shows that a water molecule is made up of one oxygen atom joined to two hydrogen atoms, so the formula of water is H 2 O. A nitrogen molecule is made up of two nitrogen ...

Scientists still needed to figure out this molecule's structure to be sure ... biochemist Erwin Chargaff found that the arrangement of nitrogen bases in DNA varied widely, but the amount of ...

The function of many biologically active molecules requires the presence of carbon-nitrogen ... transforms a molecule by introducing new functional groups into its structure.