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Translation takes place in the ribosomes that are found in the cytoplasm. This is where the messenger RNA is 'interpreted' and the new protein formed. The stages are:
Ribosomes are responsible for translating the information in messenger ribonucleic acids (mRNAs) to synthesise proteins that the cell needs to carry out its function. Protein synthesis begins with the 30S ribosomal subunit recruiting a mRNA with the help of an initiator transfer RNA and three initiation factors. Successful recruitment of the mRNA results in the formation of the 30S pre‐initiation complex, which is followed by the joining of the 50S ribosomal subunit to form the 70S ribosome. Recent studies indicate the order in which the initiation factors bind and promote the steps in initiation complex formation. The formation of the pre‐initiation/initiation complex is often the rate‐limiting step during the process of translation, as it is influenced by a number of translational regulatory mechanisms. As a result, the process of initiation can play a significant role in gene expression.
This code determines the type of amino acids and the order in which they are joined together to make a specific protein. The sequence of amino acids in a protein determines its structure and function.
The final stages of translation termination followed by the subsequent steps involved in the formation of the translation initiation complex. Step 1: dissociation of 70S ribosome into 50S subunit (grey) and 30S subunit (cyan) by ribosome recycling factor (RRF in red) and elongation factor G (EF‐G in yellow); step 2: binding of IF3 in magenta and IF2 in green to the 30S subunit; step 3: binding of IF1 in blue; step 4: binding of fMet‐tRNAfMet (orange linear object); step 5: binding of mRNA (red curved line); step 6: unfolding of mRNA; step 7: interaction of fMet‐tRNAfMet with the mRNA start codon in the P site; step 8: binding of the 50S subunit to the 30S pre‐initiation complex; step 9: dissociation of IF1, IF2 and IF3 from the 70S ribosome.
After translation, the protein passes into the channels of the rough endoplasmic reticulum (ER) for transportation. The protein is then passed from the rough ER to the Golgi apparatus inside tiny fluid-filled sacs, called vesicles. The Golgi apparatus is a system of , which are responsible for the modification, processing, and packaging of the proteins. The protein may have a carbohydrate added, to form a glycoprotein. The Golgi apparatus packages the protein in a secretory vesicle, which fuses with the cell membrane and releases the protein from the cell.
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Transcription is a process in protein synthesis
in which the genetic information from DNA is made
into a complimentary strand of mRNA.
Milon P and Rodnina MV (2012) Kinetic control of translation initiation in bacteria. Critical Reviews in Biochemistry and Molecular Biology 47: 334–348.