Minute to Understanding: What is DNA?

What is DNA? DNA or deoxyribonucleic acid is a molecule that contains the genetic code that is unique to every individual.

Think of this code as an instruction manual for making all the proteins that form our bodies and help them thrive. The information coded in DNA is hereditary, meaning that it passes from parent to child. Because of this inheritance, DNA also determines our traits: including how we are shaped and how similar we look to our parents. These traits coded in DNA will always get passed on from generation to generation.

The DNA that determines heritable traits is found in the nucleus of every single cell of our bodies. DNA is made up of two intertwined strands linked together by pairs of building blocks, known as bases, adenine, cytosine, guanine, and thymine. Bases make up the rungs of DNA's ladder-like double-stranded structure. When a base joins the side of the ladder, a nucleotide is formed. When nucleotides pair with an opposite DNA strand, the ladder is complete. An A base always pairs with a T base, and a C base always pairs with a G base. By reordering these four bases in long DNA sequences, an infinite number of combinations is possible.

This is why there is a unique DNA sequence or code for every protein in our bodies, including those that determine our traits. For example, a sequence of ATTTTG might instruct for blue eyes, while a sequence of TTTTTG might instruct for brown. By understanding how DNA is formed and knowing what unique DNA sequences encode each protein, we can start understanding how DNA sequences affect how we function and how we look. This is because DNA is the instruction manual for all the proteins that form our body and help it thrive for hopefully 100 years or more.