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.