Nucleotides – The Subunits of DNA
- DNA molecules are made up of subunits called nucleotides.
- Nucleotides consist of three parts – a sugar, a base and a phosphate.
- The sugar molecule is in the centre, with the phosphate attached to one side and the base attached to the other.
- The sugar in nucleotides is called deoxyribose, which is why the full name for DNA is deoxyribonucleic acid.
DNA molecules are made up of subunits called nucleotides.
- All nucleotides in DNA contain the same sugar and phosphate, but there are four different bases, and consequently four different nucleotides.
- The four bases are guanine, cytosine, adenine and thymine, but these are usually just referred to by their first letter – G, C, A and T respectively.
- Since nucleotides differ only in their type of base, they are also referred to by the letters G, C, A and T.
There are four different nucleotides in DNA – each with a different base.