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

A) DNA

B) ribosome

C) mRNA

D) protein

The answer is proteins.

Proteins are made of amino acids and they determine each and every function of your body, from the process of digestion to the structure of your own hairs, even your eye and skin colour just everything. It depends on the polypeptide sequence of each protein as all have a different sequence and thus will lead to different types of bonding shapes, giving each and every protein of our body a function.