BIOL 150 Lecture Notes - Lecture 10: Missense Mutation, Nonsense Mutation, Silent Mutation
Document Summary
Biol 150 principles of molecular & cellular biology. We looked at the differences between translation in eukaryotes as compared to prokaryotes. Elongation is about the same as for prokaryotes; the eukaryotic elongation factors eef-1 and eef-2 play similar roles to those of prokaryotic factors that bring in new trnas and move the ribosome forward, respectively. Finally, when the ribosome reaches a stop codon (uaa, Uag, uga), eukaryotic release factor erf terminates transcription and the mrna and the newly formed protein are released from the ribosome. The genetic code is the translation of the 64 possible codons to their associated 20 amino acids or stop. Any change to the dna sequence is called a mutation. Most mutations are silent-they have no effect on the function of the gene. Point mutations alter a single base, while insertions, deletions, usually alter a range of bases. Changing the sequence of a codon into a codon for a different amino acid is a missense mutation.
