BIO 303 Lecture Notes - Lecture 22: Aminoacyl Trna Synthetase, Rna Editing, Intron
10 May 2019
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Document Summary
Splicing in bac: endonuclease removes introns, ligase join exons to form mature mrna (smaller than regular rna) Self excision occurs in a lot of protozoans and plants. Rrna (ribozymes) imp for removal of introns. Self excision: occurs in removal of introns from primary mrna and trna transcripts produced in mitochondria and chloroplasts. Self excision occurs less in euk than bac. Includes snrnps, imp in excision (they are also removed w introns) Rna editing by insertion/deletion (base #change) and substitution (bases altered) is prevalent in mitochondrial and chloroplast rna. Prok ribosome - 70s euk ribosome- 80s. 3 trna binding sites: e, p, a rdna: rrna genes, tandem repeats separated by spacer dna. Ribosomes are larger and longer lived in euk than bacteria. trnas. Has anticodon that pairs with codon in mrna. Amino acid is linked at 3" end. For translation to start, trna gets linked to amino acids via aminoacylation and enzyme aminoacyl trna synthetase.
