The reason why the cells have more ADP than ATP molecules is that the cells have the tendency to use more ATP, rather than restore ADP molecules.
When the body produces energy, in order to be able for it to be released in the body and to be used by the body, the ATP molecules break up. During that break up of the ATP molecule it actually loses one phosphate group, thus becoming an ADP molecule. Since this process is going on constantly, the ATP molecules are constantly breaking up thus resulting in constant new ADP molecules, so they are easily becoming outnumbered.
enzyme speed up the reactions
the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a 1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by 1.661×10−271.661×10−27.
the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.
for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.