How does mRNA , tRNA and ribosomes help in the process of translation?
class 12th CBSE Biology sample paper
Answers
Translation refers to the process of polymerisation of amino acids to form a polypeptide. The order and sequence of amino acids are defined by the sequence of bases in the mRNA. The amino acids are joined by a bond which is known as a peptide bond. Formation of a peptide bond requires energy.
Therefore, in the first phase itself amino acids are activated in the presence of ATP and linked to their cognate tRNA–a process commonly called as charging of tRNA or aminoacylation of tRNA to be more specific. If two such charged tRNAs are brought close enough, the formation of peptide bond between them would be favoured energetically. The presence of a catalyst would enhance the rate of peptide bond formation.
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The cellular factory responsible for synthesising proteins is the ribosome. The ribosome consists of structural RNAs and about 80 different proteins. In its inactive state, it exists as two subunits; a large subunit and a small subunit.
When the small subunit encounters an mRNA, the process of translation of the mRNA to protein begins. There are two sites in the large subunit, for subsequent amino acids to bind to and thus, be close enough to each other for the formation of a peptide bond. The ribosome also acts as a catalyst (23S rRNA in bacteria is the enzyme- ribozyme) for the formation of peptide bond.
Answer:
The process of translation can be defined as the step in biosynthesis where the genetic code carried by mRNA is decoded to produce specific amino acid. The process is followed by transcription in which the sequence of DNA is copied into mRNA.
Transfer ribonucleic acid is a kind of RNA that helps to decode the messenger RNA sequence into protein.
tRNA is the main site in the ribosomes for the process of translation in which synthesis of protein molecule from mRNA molecules takes place.