Ribosomes play a key role in gene translation/protein synthesis.
Translation is the process by which a mature mRNA molecule is used as a template for synthesizing a new protein. Translation is carried out by ribosomes, large complexes of RNA and protein responsible for carrying out the chemical reactions to add new amino acids to a growing polypeptide chain by the formation of peptide bonds.
The genetic code is read three nucleotides at a time, in units called codons, via interactions with specialized RNA molecules called transfer RNA (tRNA). Each tRNA has three unpaired bases known as the anticodon that are complementary to the codon it reads; the tRNA is also covalently attached to the amino acid specified by the complementary codon. When the tRNA binds to its complementary codon in an mRNA strand, the ribosome ligates its amino acid cargo to the new polypeptide chain, which is synthesized from amino terminus to carboxyl terminus. During and after its synthesis, the new protein must fold to its active three–dimensional structure before it can carry out its cellular function.
Gene Translation is the process by which a mature mRNA molecule is used as a template for synthesizing a new protein.
Genes do not build a protein directly but provide the instructions for making specific proteins. Genes are typically hundreds or thousands of nucleotides long and each gene has a specific sequence of bases. Each protein has its own unique amino acid sequence that is specified by the nucleotide sequence of the gene encoding this protein. The genetic code is a set of three–nucleotide sets called codons and each three–nucleotide combination stands for an amino acid, for example AUG stands for methionine. So we can describe the flow of information in linguistic terms as both DNA and proteins contain information written in two different chemical languages (sequence of nucleotides/amino acids).
The flow of information from gene to protein is based on a triplet code and the genetic instructions for a polypeptide chain are written in the DNA as a series of non overlapping, three–nucleotide words. For example, the base triplet AGT at a particular position along a DNA strand results in the placement of the amino acid serine at the corresponding polypeptide to be produced. Codons are the triplets of nucleotide bases that code the amino acids and there are 64 possible code words – enough to specify all the amino acids. Thus, protein biosynthesis is the process in which cells build or manufacture proteins.