PRODUCTION OF RNA AND PROTEIN SYNTHESIS

Production of RNA:

RNA is produced through a process called transcription. The first step in this process is the initiation, where RNA polymerase binds to a specific region of DNA called the promoter. Then, the enzyme unwinds the DNA double helix and begins to synthesize an RNA molecule using one of the DNA strands as a template. As the RNA polymerase moves along the DNA, it elongates the RNA molecule by adding complementary nucleotides. Once the entire gene is transcribed, the RNA polymerase reaches a termination sequence, and the newly formed RNA molecule is released.

Processing of RNA:

After transcription, the newly synthesized RNA molecule undergoes several processing steps before it becomes mature and functional. In eukaryotic cells, these steps include capping, splicing, and polyadenylation. The 5’ end of the pre-mRNA is modified by adding a 7-methylguanosine cap, which protects the RNA from degradation and helps in its export from the nucleus. Splicing involves removing non-coding sequences called introns and joining together the coding sequences called exons to form a mature mRNA. Finally, polyadenylation adds a poly-A tail to the 3’ end of the mRNA, which also aids in mRNA stability and translation.

Protein Synthesis:

The process of protein synthesis occurs in two main stages: translation and post-translational modifications.

1) Translation:

Translation takes place in the cytoplasm and involves decoding the information in mRNA to synthesize a specific protein. The mRNA is read by ribosomes, which move along its length and match each codon with its corresponding amino acid. Transfer RNA (tRNA) molecules bring amino acids to the ribosome based on the codon sequence on the mRNA. The amino acids are then linked together to form a polypeptide chain according to the instructions encoded in the mRNA.

2) Post-Translational Modifications:

After translation, newly synthesized proteins may undergo various post-translational modifications to become fully functional. These modifications can include cleavage of certain amino acid sequences, addition of chemical groups such as phosphate or methyl groups, or attachment of prosthetic groups like heme or sugar molecules. These modifications can alter the protein’s structure, localization, or function.

In summary, RNA is produced through transcription, processed through capping, splicing, and polyadenylation in eukaryotic cells, and proteins are synthesized through translation followed by post-translational modifications.