Which is composed of amino acids and determines all the structures and functions of organisms?

Protein, the building blocks of proteins are amino acids, different sequences and combinations of these amino acids result in huge numbers of proteins which have a variety of functions.

the generally accepted parts of modern cell theory include: all known living things are made up of one or more cells. all living cells arise from pre-existing cells by division. the cell is the fundamental unit of structure and function in all living organisms.