The basic building block of all compounds is atoms. Compounds contain atoms of at least two different elements bonded to one another. Thus, atoms of elements are what form compounds.
An "Atom" is the basic building block of all molecules [first] and [then] biomolecules.
The basic building block of all matter is the atom.
carbon
Cells!
Carbon
Cells!
Atom
An Atom
It could be argued that the most basic building block of the body, as in all other things, is the atom. The answer that you are most likely looking for is the protein.
well it is all the organs inside you
the cell
All the universe is made from atoms.