An organic molecule, smaller than protein, that contains nitrogen

Nucleic acid

Explanation:

Nucleic acids are biopolymers, or large biomolecules, essential to all known forms of life. They are composed of nucleotides, which are the monomers made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). If the sugar is ribose, the polymer is RNA; if the sugar is the ribose derivative deoxyribose, the polymer is DNA.

not sure if this what   you'r looking for would be percent composition

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