DNA to RNA

Transcription Process of DNA to RNA

Overview of RNA Polymerase Function

• RNA polymerase plays a crucial role in the transcription process by causing DNA to uncoil at specific genes where transcription is initiated.
• The enzyme interacts with histones, causing their removal to allow access to the DNA template.

Formation of Pre-mRNA

• Pre-mRNA is synthesized from the master DNA template of the gene being transcribed.
• The synthesis involves unwinding the double-stranded DNA and creating a single-stranded RNA copy.

Processing of Pre-mRNA

• After synthesis, pre-mRNA undergoes extensive processing:
  • Introns (non-coding regions) are removed from the pre-mRNA.
  • Exons (coding regions) are retained and spliced together.
• The processed mRNA is then transported out of the nucleus.

Translation of mRNA into Protein

Reading of mRNA

• The mature mRNA travels to the ribosome in the cytoplasm where it is "read".
• The ribosome interprets the mRNA sequence in triplet codons (each consisting of three nucleotides).

Role of tRNA

• Transfer RNA (tRNA) molecules play an essential role in translation:
  • Each tRNA carries a specific amino acid corresponding to the codon being read.
  • As tRNA molecules match their anticodons to the mRNA codons at the ribosome, they bring in amino acids that link together to form a polypeptide chain.

Polypeptide Formation

• The resulting polypeptide represents the first degree of protein structure (1° protein).
• Structure and functionality of proteins depend on the sequence and number of amino acids in this polypeptide chain.