What is a Nucleic Acid?
A nucleic acid is one of the four major types of macromolecules essential for all known forms of life. They are large biomolecules that play a central role in storing, transmitting, and expressing hereditary information. The two main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).
Section 2: The Building Blocks of Nucleic Acids
Nucleic acids are polymers, meaning they are long chains made of repeating smaller units called monomers. The monomer of a nucleic acid is called a nucleotide. Each nucleotide is composed of three components: a five-carbon sugar (either deoxyribose in DNA or ribose in RNA), a phosphate group, and a nitrogen-containing base.
Section 3: A Practical Example - DNA
Deoxyribonucleic acid (DNA) is a prime example of a nucleic acid. It consists of two long chains of nucleotides coiled into a double helix. The sequence of its four nitrogenous bases—adenine (A), guanine (G), cytosine (C), and thymine (T)—forms a code that contains the instructions for building and maintaining an entire organism.
Section 4: Why Are Nucleic Acids Important?
Nucleic acids are fundamentally important because they carry the genetic blueprint for life. DNA serves as the permanent storage for genetic information, while RNA has various roles, including acting as a messenger (mRNA) to carry instructions from the DNA in the cell's nucleus to the ribosomes, where proteins are made. This flow of information from DNA to RNA to protein is a central tenet of molecular biology.