Protein synthesis: Difference between revisions
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Revision as of 00:51, 15 November 2011
Protein synthesis is the creation of proteins via transcription and then translation on a ribosome, involving RNA polymerase, primers, mRNA, tRNA and rRNA.it occurs in both Eukaryotic and Prokaryotic cells although there are certain differences like splicing occurs in different places and of course there isn't a nucleus in prokaryotes so no movement between membranes is involved to get the mRNA strand out of the cell.
Transcription
Transcription is the copying of the DNA in the nucleus to RNA. For a gene to be synthesised into a protein it needs to be expressed by certain pathways within the cell.
Splicing
Splicing occurs in the nucleus
Translation
Componants involved
mRNA
mRNA is a copy made of the DNA by RNA polymerase II and spliced to take out all the introns. This is a single polynucleotide strand that have codons made up of Adenine, Guanine, Cytosine and Uracil and instead of a deoxyribose in the sugar phospate backbone there is a ribose molecule.
tRNA
This is a single polynucleotide strand that folds back on itself to form hydrogen bond in the shape of a clover leaf. This molecule on one end has an anticodon which is complimentary to the codon on the the mRNA strand which it attaches to. On the other end there is a specific protein that is able to detach and form part of a polypeptide chain.
Ribosome
The Ribosome is the location of the translation of proteins, the Ribosome has 3 tRNA binding sites the P site which holds the tRNA molecule with the polypeptide strand, the A site which binds to the tRNA molecule with the next amino acid to by hydrolysed and the E site which holds the tRNA molecule to be discharged[1]. The mRNA strand is attached to the tRNA strand by Hydrogen bonds and also attached to the ribosome.
The Mechanism
Once the mRNA strand has bound to the