the ribosome Flashcards
what are ribosomes?
large macromolecular complexes of RNA and protein
how many subunits does the ribosome have?
2
small and large
what does the large subunit do?
catalyzes peptide bond formation (peptidyl transferase center)
what does the small subunit do?
mediates interactions between mRNA and tRNA (decoding center)
describe the orientation of RNA and proteins in the ribosome;
Inside of the ribosome is mostly RNA and the outside has protein subunits. Some of the protein arms extend into the RNA regions
The arms are highly basic and are thought to help with backing the negatively charged rRNA phosphate backbones
what is the L7/L12 stalk?
of the large subunit of bacterial ribosomes includes protein L10 and multiple L7/12
The L12 CTDs can reach far out into solution to catch translation factors and bring them to the ribosomal factor binding site, effectively restricting factor diffusion and leading to rapid recruitment of charged tRNAs
In eukaryotic ribosomes the stalk is composed of P0, P1 and P2 proteins
waht is the sarcin-ricin loop?
longest conserved sequences in 23S rRNA. Targeted by alpha-sarcin.
is the complexity of an organisms life proportional to the complexity of the ribosome?
yes
what is special about the archaea ribosome?
has an extra layer of protein
what do lower eukaryotes have?
protein-RNA shell
waht do high eukaryotes have?
a layer of RNA tentacles
what does the decoding region of 16S/18S rRNA do?
mediates the interaction between tRNA and mRNA in the small subunit
what does the peptidyl transferase unit in the 23S/28S rRNA do?
catalyzes the formation of the peptide bond
what is the 23S rRNA of alphaproteobacteria cleaved into ?
5.8s, 14S and 16S
what does the 5.8S rRNA in eukaryotes code for in bacteria?
the 5’ end of the large rRNA
