Lecture 25: Translation/Point Mutations

Flashcards for reviewing translation and point mutations.

Ribosome

Catalyzes peptide bond formation during translation.

tRNA

Links information in mRNA codons with specific amino acids in protein.

tRNA Synthases

Attaches amino acids to tRNAs.

Translation

mRNA-directed polypeptide synthesis

tRNA

Acts as adapters to bring amino acids to mRNA in ribosome.

Anticodon

A specific sequence of three nucleotides in tRNA that binds to a mRNA codon

Charged tRNA

Covalently attaches a specific amino acid.

Aminoacyl-tRNA Synthetase

Catalyzes attachment of an amino acid to the 3’ end of tRNA

Aminoacyl-tRNA

Carries an activated amino acid.

Raney Nickel Experiment

Experiment that proved tRNA is the adapter between protein and mRNA.

Tetracycline

blocks binding of aminoacyl-tRNA to A-site of ribosome.

Ribozyme

rRNA, not protein, catalyzes peptide bond formation.

A Site

Entry site for incoming tRNAs

P Site

Site where peptidyl-tRNA carrying the growing polypeptide chain sits.

Site for exiting 'spent' tRNAs.

E site

Shine-Dalgarno Sequence

Sequences just upstream the AUG on mRNA that ribosome is positioned on in prokaryotes

UAA, UAG, UGA

Codons that signal a translation stop signal.

Polyribosome

Multiple ribosomes translate the same mRNA sequentially .

Mutations

Changes in DNA that replace, delete, or insert nucleotides.

Point Mutation

Single base pair change.

Missense Mutation

Change one codon for another.

Nonsense Mutation

Premature stop codon.

Silent Mutation

No effect on amino acid sequence.

Insertions and Deletions

Additions or deletions of nucleotide pairs in a gene.

Frameshift Mutation

Alters translation reading frame.

Post-translational modifications

Chemical modifications of sugars/lipids/phosphates after translation

N-terminal signal peptide

A sequence that directs the complex to the ER