DNA can be split into non-coding and coding DNA.
Coding and Non-Coding DNA
Coding DNA codes for different proteins. Non-coding DNA does not code for proteins or amino acids.
- Only 1% of DNA is made up of protein-coding genes
- The other 99% is non-coding.
- Non-coding DNA does not provide instructions for making proteins.
- Scientists thought non-coding DNA was "junk" but this isn't correct.
Introns and Exons
An intron is a portion of a gene that doesn't code for amino acids.
- The parts of the gene sequence that are expressed in a protein are called exons.
- The parts of a gene that aren't expressed are called introns - they come in between exons.