How does DNA base pairing work?
1 Answer
In DNA base pairing, Adenine pairs with Thymine and Cytosine pairs with Guanine.
Explanation:
Adenine and Guanine are purines and Cytosine and Thymine are pyrimidines.
Dictated by specific Hydrogen bonding patterns, Watson and Crick base pairs allow the DNA helix to maintain a regular helical structure.
Pairing of a specific purine to a specific pyrimidine is due to the structure and properties of these bases. Matching base pairs form H - bonds. Adenine and Thymine have 2 sites where they form
H - bonds. Cytosine and Guanine have 3 sites.
Bonded together, these base pairs form the rungs of the DNA ladder or double helix.
For each of the four nitrogenous bases a specific tautomeric form must be incorporated for proper bonding, stability and attachment to the sugar phosphate backbone of DNA.