BIOL 11000 Lecture Notes - Lecture 15: Transfer Rna, Streptomycin, Ribosome
18 Oct 2016
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Document Summary
Ribosomes composed of small and large protein subunits, which have different functions. Made of proteins and rrna (ribosomal rna) Small subunit acts like conveyor belt for mrna. Large subunits accepts trna and joins amino acids. Prokaryotic ribosomes smaller & slightly different, allowing antibiotics (tetracycline, streptomycin) to inactivate them without interfering with patient"s ribosomes. Translation trna (transfer rna) carries amino acids from cytoplasm ribosomes. Sets of 3 nucleotides of mrna form codons, which are complimentary to sets of anticodons on trna. Almost all codons the same across all organisms so far investigated. Each codons corresponds to an amino acid. Redundancy: more than one codon codes for the same amino acid. One codon never codes for more than one amino acid. 1. mrna leave nucleus (after transcription) and enters a ribosome. 2. trna enters ribosome at a site. Energy used to join the amino acid on the trna in the a site to the growing protein.
