Complementary Base Pairing Between tRNA and mRNA
- In protein synthesis, tRNA and mRNA work like puzzle pieces.
- They ensure the correct amino acids are added to a growing polypeptide chain.
- This precise pairing is essential for accurate translation of genetic information into proteins.
The Role of Codons and Anticodons
Definition
Codon
A codon is a sequence of three nucleotides in DNA or RNA that specifies a particular amino acid or a start/stop signal during protein synthesis.
The codon AUG codes for the amino acid methionine and also serves as the start signal for translation.
What are Anticodons?
Definition
Anticodon
An anticodon is a sequence of three nucleotides on a transfer RNA (tRNA) molecule that is complementary to a codon on a messenger RNA (mRNA) strand.
If the mRNA codon is AUG, the anticodon on the tRNA will be UAC.
How Complementary Base Pairing Works
The Process of Translation
- Ribosome Binding: Translation begins when a ribosome attaches to the mRNA strand.
- tRNA Recognition: A tRNA molecule with an anticodon complementary to the first mRNA codon binds to the mRNA.
- Amino Acid Transfer: The tRNA carries a specific amino acid that corresponds to the mRNA codon. This amino acid is added to the growing polypeptide chain.
Remember, adenine pairs with uracil (not thymine in RNA), and cytosine pairs with guanine.
Why Complementary Base Pairing is Critical
- Complementary base pairing ensures that the genetic code is translated accurately.
- Without this precision, proteins could be assembled incorrectly, leading to dysfunctional or harmful proteins.
- Don't assume that tRNA and mRNA pair permanently.
- In reality, the pairing is temporary, allowing the tRNA to deliver its amino acid and then detach.
The Role of tRNA in Translation
Structure of tRNA
tRNA molecules have a unique cloverleaf structure with two critical regions:
