Any enzyme that catalyzes the addition or removal of the elements water (hydrogen, oxygen), ammonia (nitrogen, hydrogen), or carbon dioxide (carbon, oxygen) at double bonds, as defined in physiology. Decarboxylases, for example, remove carbon dioxide from amino acids, while dehydrases eliminate water.
Boron having an atomic number of 5 means that it will have 5 protons. 11 atomic mass units in total. Neutrons also have a atomic mass unit of 1. So there are 6 neutrons
