A look at the process of protein synthesis
Protein synthesis definition
Once the anticodon and codon sequences are bound remember, they are complementary base pairs , the tRNA presents its amino acid cargo and the growing polypeptide strand is attached to this next amino acid. Proteins are long chains of amino acids , and the exact sequence of the amino acids determines the final structure and function of the protein. The signal more In this step, the ribosome reads the nucleotides of mRNA three by three, in units called codons , and matches each to three nucleotides on the tRNA, called the anticodon. This refers to the fact that DNA contains the information necessary for the cell to build one very important type of molecule: the protein. Figure a Termination of translation. Once the sequence of amino acids is successfully assembled in a protein, the two ribosome sub-units separate from each other, to be joined again for later use. Recognition of the initiation codon is largely mediated by base-pairing interactions between the AUG codon and the anticodon sequence in a methionyl initiator tRNA Met-tRNA i ; the methionine is not modified with a formyl group in eukaryotes as it is in prokaryotes. After L. Figure 1. The substrate on which translation takes place is the ribosome. Their function is still a mystery, but the process called splicing removes these non-coding regions from the pre-mRNA transcript Figure 3. Nonsense suppressor mutations It is interesting to consider the suppressors of the nonsense mutations that Brenner and co-workers defined. Many of these nonsense suppressor mutations are known to alter the anticodon loop of specific tRNAs in such a way as to allow recognition of a nonsense codon in mRNA. The triplets within the gene on this section of the DNA molecule are used as the template to transcribe the complementary strand of RNA Figure 2.
Some of these critical biochemical reactions include building larger molecules from smaller components such as occurs during DNA replication or synthesis of microtubules and breaking down larger molecules into smaller components such as when harvesting chemical energy from nutrient molecules.
This reaction is autocatalytic and can take place in vitro.
This preferred set of bases around the initiation codon is called the Kozak sequence, named after its discoverer, Marilyn Kozak. The remaining exons are pasted together. Ribosomes consist of two parts, a large subunit and a small subunit.
Thus tRNA transfers specific amino acids from the cytoplasm to a growing polypeptide. Commonly, an mRNA transcription will be translated simultaneously by several adjacent ribosomes.
The transcript is decoded into a protein with the help of a ribosome and tRNA molecules.
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