DNA is fundamental to the biology of all life on Earth, but how many of us actually know what it is or what it's made of?

The structure of a nucleotide, consisting of a phosphate group (left), a pentose sugar molecule (middle), and a nitrogenous base (right). (Image: Public Domain) Ribonucleotides are the building blocks ...

How can just four nitrogenous bases--adenine, cytosine ... Furthermore, how could a three-nucleotide code be "read" by the protein-forming machinery of the ribosome? Was it an overlapping or ...

and a nitrogenous base. Adjacent ribose nucleotide bases are chemically attached to one another in a chain via chemical bonds called phosphodiester bonds. Unlike DNA, RNA is usually single-stranded.