The Role of RNA in Gene Expression and Protein Synthesis

The Role of RNA in Gene Expression and Protein Synthesis


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  • Source: Microbioz India

  • Date: 21 Dec,2023

RNA (ribonucleic acid) has an important role in the process of gene expression as well as protein synthesis. Gene expression refers to the use of information encoded in DNA to direct the synthesis of functional gene products, specifically proteins. During this process RNA molecules act as intermediaries, they facilitate transfer of genetic information from DNA in the nucleus of cells to protein synthesis machinery in cytoplasm.

There are three main types of RNA involved; messenger RNA (mRNA), transfer RNA (tRNA) and ribosomal RNA (rRNA).

Messenger RNA (mRNA):

  1. Transcription: The initial step in gene expression is transcription where a specific segment of DNA is used as a template for synthesizing complementary mRNA strand; this happens within cell nucleus.
  2. RNA Polymerase: mRNA synthesis is catalyzed by enzymes known as RNA polymerases which add complimentary RNA nucleotides onto growing mRNA strands.
  3. mRNA Processing: Before crossing over into cytoplasm, mature mRNAs undergo multiple changes including 5’ cap addition and polyA tailing that help stabilize them during translation.
  4. Transport to the Cytoplasm: After processing, mature mRNAs are transported out of the nucleus into cytoplasm where protein synthesis takes place.

Transfer RNA (tRNA):

  1. Translation: Within cytoplasm, mRNA serves as a template for protein synthesis through translation; tRNAs have significant roles in this process.
  2. Amino Acid Transport: Every tRNA molecule carries one particular amino acid to ribosome – subcellular machine responsible for making proteins.
  3. Anticodon Recognition: In tRNA, anticodon region base pairs with corresponding codon on mRNA thus ensures accurate incorporation of correct amino acid into growing polypeptide chain.

Ribosomal RNA (rRNA):

  1. Ribosome Structure: These cellular structures consist mainly of rRNA molecules together with proteins and act as centers for protein synthesis.
  2. Catalysis of Peptide Bonds: Ribosomes help in joining amino acids by forming peptide bonds that link them together into polypeptide chains.
  3. Reading the mRNA Code: As ribosome moves along mRNA molecule, it reads codons facilitating binding of appropriate tRNA molecules with their specific amino acids.

This whole process which can be summarized as central dogma of molecular biology involves transfer of genetic information from DNA to RNA finally resulting into proteins. RNA acts as a messenger that conveys genetic code from nucleus DNA to cytoplasmic ribosomes where protein synthesis occurs. It is through this intricate and highly regulated process that accurate translation of genetic information into functional proteins is achieved, playing a role in cellular activities and traits expression in living organisms.

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