Chargaff’s rules explained

Chargaff’s rules state that DNA from any species of any organism should have a 1:1 stoichiometric ratio of purine and pyrimidine bases (i.e., A G=T C) and, more specifically, that the amount of guanine should be equal to cytosine and the amount of adenine should be equal to thymine. This pattern is found in both strands of the DNA. They were discovered by Austrian-born chemist Erwin Chargaff, in the late 1940s. First parity rule The first rule holds that a double-stranded DNA molecule, globally has percentage base pair equality: %A = %T and %G = %C. The rigorous validation of the rule constitutes the basis of Watson-Crick pairs in the DNA double helix model. Second parity rule The second rule holds that both %A ≈ %T and %G ≈ %C are valid for each of the two DNA strands. This describes only a global feature of the base composition in a single DNA strand. #ChargaffsRules #DNA #RNA #Adenine #Guanine #Cytosine #thymine #genetics #dnaReplication #chargaffsRuleOfDna #chargaffsRuleProblems #watsonAndCrick #chargaffsRuleExplained #dnaBasesPairing #complementaryBasePairing #DNASequence #dnaComplementarySequence #dnaSequenceComplementaryStrand #andThymine #dnaSemiConservativeReplication #replicationFork #dnaReplicationSong #dnaTranscription #initiation #elongation #termination