What is noncoding DNA?

Non-coding DNA (ncDNA) refers to the components of an organism’s genome that do not code for amino acids, the building blocks of proteins. However, they do play a role in the control of gene activity. The amount of noncoding DNA varies significantly from one organism to another. 

In most organisms, only about 1% - 2% of the total DNA is composed of protein-coding genes. The remaining 98% - 99% is made up of noncoding DNA. Non-coding DNA does not provide instructions for protein synthesis. Instead, some serve functional roles such as gene expression, while others have no known function. Noncoding DNA contains several types of regulatory elements such as promoters, enhancers, silencers, and insulators. Each of these regulatory elements provide unique binding sites for different types of proteins.