How can just four nitrogenous bases--adenine, cytosine, guanine, and uracil--possibly code for all 20 amino acids? Thus, early researchers quickly determined that the smallest combination of As ...

Ribonucleic acid (RNA) is a linear molecule composed of four types of smaller molecules called ribonucleotide bases: adenine (A), cytosine (C), guanine (G), and uracil (U). RNA is often compared ...