Biochemistry 2280A Lecture Notes - Lecture 23: Aminoacyl Trna Synthetase, Stop Codon, Nonsense Mutation
24 Dec 2016
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Document Summary
Key cycle for regulation mrna to protein trna: genetic code, aminoacyl trna, ribosome, mechanism of translation, termination, antibiotics. The genetic code spells out the amino acid sequence in 3 letter words called codons. We need at least 20 codons since there are 20 amino acids. 4 to the power of 3 is 64. Increases the chance of a functional protein in the case of a single base mutation. Proteins are more likely to retain their function. Converting one base in the sequence, results in a single amino acid change: e. g. Changing gcc into ggc changes ala into gly: causes change in the protein. In many cases not too bad in repercussions. Insertion or deletion of bases can change the reading frame of a protein from the point of the mutation onward: very problematic will kill the function of the protein.
