deoxyribonucleic acid

[ dee-ok-si-rahy-boh-noo-klee-ik, -nyoo-, -ok-si-rahy- ]


, Genetics.
  1. DNA.

deoxyribonucleic acid

/ diːˌɒksɪˌraɪbəʊnjuːˈkleɪɪk /


  1. the full name for DNA

deoxyribonucleic acid

/ dē-ŏk′sē-rī′bō-no̅o̅-klēĭk /

  1. See DNA

Discover More

Word History and Origins

Origin of deoxyribonucleic acid1

First recorded in 1930–35; deoxy- + ribonucleic acid


Discover More

More About Deoxyribonucleic Acid

What is deoxyribonucleic acid?

Deoxyribonucleic acid—better known by the abbreviation DNA—is a large, complex molecule that allows cells to function and carries the genetic code that determines the traits of a living organism.

DNA is in every cell of every living thing. Some viruses also have DNA.

Life as we know it wouldn’t exist without DNA—it contains the instructions that cells need to function. DNA is found in the cell nucleus, and every cell in an organism has the exact same copy of DNA that is in every other cell. Each cell uses its copy of DNA whenever it needs to make a protein. Proteins have many essential jobs within a living thing. For example, your immune system produces proteins called antibodies to fight germs.

The information that’s in DNA controls the development of specific traits, such as the shape of a leaf or the color of hair. Specifically, such traits are determined by genes, which are segments of DNA within strands called chromosomes. The set of all information contained in the DNA of any living thing—all of its inheritable traits—is called its genome.

Technically speaking, deoxyribonucleic acid is a type of macromolecule (a very large molecule—one composed of hundreds of thousands of atoms) known as a nucleic acid. Nucleic acids are made of smaller molecules known as nucleotides, which are made of a phosphate, a sugar, and nitrogen bases. The four nitrogen bases in DNA are adenine (A), thymine (T), guanine (G), and cytosine (C).

DNA has a shape known as a double helix, which resembles a spiraled ladder. The DNA ladder is built from two very long strands of nucleotides with the nitrogen bases pairing together to form the rungs of the ladder. The bases form base pairs, with adenine always paired to thymine and guanine always paired to cytosine. The phosphate and sugar within the nucleotide act as the sides of the ladder.

Because DNA only exists within the cell’s nucleus, the genetic information must be distributed somehow. This is one of the roles of RNA (ribonucleic acid), which is a macromolecule that works alongside DNA to make proteins. During this process, RNA acts as a kind of copy of the DNA that carries its genetic information outside of the cell nucleus.

We took a microscopic look at the differences between DNA, RNA, and mRNA, and their vital roles. Read all about it here!

Why is deoxyribonucleic acid important?

Deoxyribonucleic acid is ancient, but its discovery was relatively recent. In 1869, chemist Friedrich Miescher documented a kind of molecule that had never been studied before—nucleic acid. It wasn’t until around the 1930s that the terms deoxyribonucleic acid and DNA began to be used. In the 1950s, the work of biophysicist Rosalind Franklin and biologists James Watson and Francis Crick revealed DNA’s double helix structure.

Cells cannot make proteins without DNA. DNA acts as a set of instructions for any protein that needs to be made.

The study of DNA is central to the field of science known as genetics. DNA contains genetic information that is passed down from one generation to another. You get roughly half of your DNA from your mother and half from your father. This is the reason children look similar but not identical to their parents.

Despite the vast range of different physical traits that people can have, the DNA of all humans is more than 99% identical. Human DNA is made of billions of nitrogen bases, and even minor differences can result in two people that look very different. (Identical twins are born with the exact same DNA.)

The order of nitrogen base pairs is what makes every person and every living thing unique. For example, minor differences in this sequence determine whether a person will have brown eyes or blue eyes.

Did you know ... ?

Deoxyribonucleic acid is analyzed in the study of human evolution. Our closest living biological relatives are chimpanzees and bonobos, whose DNA is over 98% identical to ours. This fact has contributed to the theory that humans and chimpanzees share a common ancestor that lived millions of years ago.

What are real-life examples of deoxyribonucleic acid?

This illustration shows a simplified rendition of the double helix structure of deoxyribonucleic acid.

Deoxyribonucleic acid is crucial to life, and learning about it is a crucial part of the study of biology.


Quiz yourself!

True or False?

Deoxyribonucleic acid is essential to life because it contains instructions for the production of proteins.