What are nucleic acids?
Nucleic acids are a group of biological molecules formed when many building units called nucleotides link together in a line.
"In a line" means they form a chain, one after another, with no branching. That makes them linear polymers.
The elements in nucleic acids
Carbon (C) · Hydrogen (H) · Oxygen (O) · Nitrogen (N) · Phosphorus (P)
Of all the biological molecules studied so far, this is the only one containing phosphorus. It is a way of recognising them.
The most genetically important of the four biological molecules
Among the main organic molecules in living matter, nucleic acids are the most important genetically.
What makes them different?
Carbohydrates, lipids and proteins build or run the body. Nucleic acids do neither — they carry the information about how to do it. The instructions for building a protein are written in them.