Please enable JavaScript.
Coggle requires JavaScript to display documents.
Complementary base pairing - Coggle Diagram
Complementary base pairing
Adenine & Thymine
Forms 2 hydrogen bonds
A partially positivehydrogen in adenine bonds with a pertially negative oxygen in thymine
A hydrogen atom in thymine interacts with a nitrogen atom in adenine
Guanine & Cytosine
Forms 3 hydrogen bonds
A hydrogen atom on guanine bonds with an oxygen atom on cytosine.
Another hydrogen atom on cytosine bonds with a nitrogen atom on guanine.
A third bond forms between a hydrogen atom on guanine and an oxygen atom on cytosine.
A bit stronger that A&T because of the extra bond
Importance of complementary base pairings in DNA
Accurate replication
During DNA replication, the two strands of the double helix separate, and each serves as a template for a new complementary strand, resulting in semiconservative DNA replication.
Complementarity ensures that the correct bases are added to the growing strand.
If the template strand has a sequence of A-T-G-C, the new strand will form with T-A-C-G. This precision is critical for maintaining genetic integrity
Stability of the double helix
The hydrogen bonds between complementary bases stabilize the DNA double helix.
While individual hydrogen bonds are weak, the sheer number of bonds across the entire length of DNA provides significant cumulative strength.
At the same time, the bonds are weak enough to allow the strands to separate during replication and transcription
Universal genetic code
Complementarity also plays a role in the universality of the genetic code.
The same base-pairing rules apply across all organisms, from bacteria to humans.
This universality underscores the shared evolutionary history of life on Earth