BIOL 1F90 Lecture 26: LECTURE 26a
5 Dec 2016
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Document Summary
Bring together mra and trna in an organized way. Ribosomes are found in the cytosol of prokaryotes or cytoplasm of eukaryotes. Bacterial and eukaryotic ribosomes contain structural differences: exploited by antibiotics to inhibit bacterial translation only, bacterial and eukaryotic transcription figure last laecture. Overall ri(cid:271)oso(cid:373)e shape deter(cid:373)i(cid:374)ed (cid:271)y rrna" trna"s (cid:271)i(cid:374)d to the ri(cid:271)oso(cid:373)e at three dis(cid:272)rete sites: a site: aminoacyl site(new trna, p site: peptidyl site(polypeptide chain, e site: exit site. Assembly of mrna, the first trna, and the ribosomal subunits: small and large ribosomal subunits exist separately when not participating in translation. Requires help of ribosomal initiation factors: proteins that facilitate interactions between components also requires energy. Requires input of energy in the form of gtp: at two different stages they hydrolyze gtp and harness energy to bring together factors during initiation. In prokaryotes: facilitated by a ribosomal-binding sequence (cid:374)ear the (cid:1009)" e(cid:374)d of the mrna.
