adenine molecule, structural chemical formula, ball-and-stick model, image purine nucleobase

adenine purine nucleobase nucleobases nucleic acids molecule molecular structure chemical formula isolated model c5h5n5 atom chemistry rna laboratory science nucleotide acid biology dna information research base illustration deoxyribonucleic footed code composition gene medical medicine test biochemistry complementary genome organism pair skeletal compound element vitamin icon line structural ball- -stick image ball- -stick nucleobase