GENE 320 Lecture Notes - Lecture 14: Joshua Lederberg, Petri Dish, Bacteriophage
Document Summary
Translation in eukaryotes - requires more factors for initation, elongation, and termination than in bacteria - eukaryotes are more complex* Ribosomes are not free oating; instead are associated with endoplasmic reticulum. Small and large ribosomal subunits mrna molecule - helps build polypeptide stand. Initiation factors bind to small subunit and attract mrna trna binds to aug codon of mrna in p site forming initiation complex. Subsequent aminoacyl trna is poised to enter the. Termination: signaled by stop codons: uag, uaa, uga in the a site. Gtp dependent release factors stimulated hydrolysis of polypeptide from peptiyl trna released from translation complex (release of polypeptide strand) Polysomes (polyribosomes) - mrna with several ribosomes translating at once. As mrna passes through ribosome, its free to associate with another small subunit. Ribosome are larger and longer lives than bacteria* 5" end of mrna capped with 7-methylguanosine residue at maturation which is essential for translation. Poly a tail added at 3" end of mrna.
