The Genetic Code Is Universal
- The same codons (three-base sequences) specify the same amino acids in almost all organisms.
- There are only a few rare exceptions (e.g., some mitochondrial codons differ slightly), but these do not change the overall principle.
Definition
Codon
A codon is a sequence of three nucleotides in DNA or RNA that specifies a particular amino acid or a start/stop signal during protein synthesis.
The codon AUG codes for methionine in bacteria, plants, and animals alike.
TipExceptions (like in mitochondria or some protists) are rare and do not undermine the overall universality.
Implications of Universality
- Since the genetic code is the same, genetic information is transferable between species.
- A gene from one organism can be inserted into another, and the recipient will still produce the correct protein.
- This is why genetic engineering (e.g., inserting the human insulin gene into bacteria) is possible.
Consistency in Protein Synthesis
- All life forms use the same fundamental process, where DNA is transcribed into RNA, which is translated into proteins.
- This conserved mechanism highlights a common evolutionary blueprint.
