Will thymine ever attach to cytosine? Why or why not?
Answers
Answer:
It's the basic genetic principle on molecular biology that we all Learn. That is Adenine bonds with thymine and guanine with cytosine . No one wonders why. …..
The answer is simple
It's due to the perfect match between the hydrogen donor and acceptor btw the two. ie ., Adenine and thymine forms 2 hydrogen bonds, while guanine and cytosine forms 3 hydrogen bonds. If other wise they would be highly unstable.
Helps to maintain the structure of the double helix. As you all know the The diameter of the B-DNA is ~20 Angstroms, and the distance between base pairs is ~3.4 Angstroms. The Purin's ( Adenine and guanine) have two organic rings and pyridines ( cytosine and guanine) have only one ring. ( See their structure Purine and Pyrimidine Structures. ) So Adenine ( 2 ringed ) combines with thymine ( 1 ring ) maintaining the anatomy of helix other wise it will be too wide or too narrow.