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| The genetic code is a set of rules for translating information encoded in [[DNA|DNA]] into proteins through [[RNA|RNA]] in [[genes|genes]]. The code is read 5' to 3' direction in a fixed reading frame beginning from the start [[codon|codon]] (AUG)<br>
| | See [[Genetic_code|Genetic Code]] |
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| The code has the following features:
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| #Codes for a single amino acid whereby the bases are read in sets or groups of 3s called a TRIPLET CODE or [[Codon|CODON]]. Example is UUU for [[Phenylalanine|Phenylalanine]], CGC for [[Arginine|Arginine]].
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| #Is non-overlapping meaning that the triplets (group of 3s) are read separately. A deletion or insertion of bases can cause a frameshift mutation<ref>Hartl,&amp;amp;amp;amp; Jones,. Genetics: analysis of genes and genomes, 7th Edition(2009) p.g 368. Jones &amp;amp;amp;amp; Bartlett. ISBN 978-0-7637-7216-1</ref>.
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| #Is [[Degenerate code|degenerate-]] more than one triplet can code for a particular amino acid. This occurs due to redundancy; there are four different bases read in groups of three to give 64 possible combinations but only 20 amino acids (4<sup>3</sup> = 64). Examples are; [[serine|serine]] has the following ( UCU, UCC, UCA, UCG, AGU, AGC), [[glycine|glycine]] which has (GGU, GGC, GGA, GGG). These codons are called synonymous codon <ref>Hartl,&amp;amp;amp;amp; Jones,. Genetics: analysis of genes and genomes, 7th Edition(2009) p.g 370. Jones &amp;amp;amp;amp; Bartlett. ISBN 978-0-7637-7216-1</ref>. However, some amino acid have only one codon which specifies it on the genetic code, example is [[tryptophan|tryptophan]] (UGG) and [[methionine|methionine]] (AUG), also, the [[stop codon|stop codon]] has three codons which specifies it (UGA, UAA, UAG)<sup></sup>
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| #According Berg ''et al.'' (2012), "the code lacks punctuation (comma)" <ref>Berg JM, Tymoczko JL, &amp;amp;amp;amp; Stryer L. Biochemistry, 7th Edition (2012) p.g 133. Pearson International. ISBN 1-4292-7635-5</ref>.
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| The genetic code is known as universal code but some alterations have been noticed recently. Example is human [[Mitochondria|mitochondrial]] whereby UGA codes for [[tryptophan|tryptophan]], AGA & AGG code for [[stop codon|stop codon]]; this occurs because mitochondrial DNA encodes a distinct set of tRNAs<ref>Berg JM, Tymoczko JL, &amp;amp;amp;amp; Stryer L. Biochemistry, 7th Edition (2012). Pearson International. ISBN 1-4292-7635-5</ref>.<br>
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| === References ===
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| <references />
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