A nucleotide is the basic unit that makes up DNA.
A singular nucleotide is made up of x3 components:
Bases
There are x4 different nitrogenous bases that comprise DNA.
1. Adenosine
2. Thymine
3. Cytosine
4. Guanine
They come under x2 groups depending on their shape and chemical structure.
Pyrimidines
Thymine and Cytosine are the smallest of the 4 bases. With only 1 ring in their structure.
Point to Remember!
*** In RNA, Thymine is replaced by Uracil ***
Purines
Adenosine and Guanine are the biggest of the 4 bases. Their structure contains a pyrimidine ring + a smaller 5 sided ring. Therefore making a 2 ringed structure.
Key points
A nucleotide (base + sugar + phosphate) is the building blocks for nucleic acid (DNA & RNA)
A nucleoside (base + sugar)
Nucleotides can serve as energy carriers in the form of ATP (Adenosine TriPhosphate)
Nucleotides can aid in cell signalling e.g. cyclicAMP (cAMP)