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Renin Angiotensin Mechanism.

Translation / Protein synthesis.

 

  • Takes place in cytoplasm.

  • Messenger RNA (mRNA) brings instructions for making ONE protein from the nucleus to the ribosome.

  • The mRNA binds with a small ribosomal unit.

  • This binding initiates binding of a large ribosomal unit with the small ribosome unit-mRNA complex to form an assembly line for protein production.

  • The large Ribosomal unit has three binding sites

    • A: Attachment site.

    • P: Pairing Site.

    • E: Exit site.

  • The completion of small ribosomal unit-mRNA- large ribosome unit complex activates movement of tRNA.

  • Transfer RNA (tRNA) molecules bring amino acids from the cytosol into the ribosome to build the protein.

  • Different types of tRNA bring different types of amino acids to the ribosome.

  • Different types of tRNA also have different 3 base anticodon sequences that bond to mRNA “codons”. 

  • The codon-anticodon binding takes place at the attachment site.

  • The start codon is the first codon of a messenger RNA. It is always AUG which stands for amino acid Methionine.

  • tRNA’s will only bond to mRNA where the mRNA codon complements the tRNA anticodon.

  • Molecules in the ribosome covalently bond adjacent amino acids together to form the protein chain at the P site.

  • The empty tRNA molecule leaves the complex at E site to bind with another amino acid.

  • As the process continues, the length of amino acids grows.

  • When the mRNA stop codon appears in the ribosome, the complete protein chain is released and the small ribosomal unit-mRNA- large ribosome unit complex gets separated.

Commonly Asked Questions.

  1. Write a short note on “Protein Synthesis”.

  2. Write a note on “translation”.
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