If you start with a DNA sequence of GGG in a gene, explain how this coded information is ultimately going to result in an amino acid which is coded for by GGG. In other words, work through the protein synthesis pathway and the codons and anticodons involved and in what molecules they are found
The Correct Answer and Explanation is:
The DNA sequence GGG in a gene plays a critical role in the process of protein synthesis, which involves two main stages: transcription and translation. Each of these steps helps convert the genetic code into a functional protein.
First, during transcription, the DNA sequence is copied into messenger RNA (mRNA) inside the nucleus. The DNA triplet GGG is transcribed into the mRNA codon CCC. This happens because RNA uses the base cytosine (C) to pair with guanine (G), and uracil (U) instead of thymine (T) to pair with adenine (A). Since the DNA template strand reads GGG, the complementary RNA codon becomes CCC.
Next, the mRNA leaves the nucleus and enters the cytoplasm, where translation takes place. This process involves ribosomes and transfer RNA (tRNA) molecules. The ribosome reads the mRNA codons in groups of three nucleotides. For the mRNA codon CCC, a tRNA molecule with the anticodon GGG binds to it. This anticodon-codon pairing follows standard base-pairing rules, ensuring the correct amino acid is added to the growing protein chain.
Each tRNA molecule carries a specific amino acid corresponding to its anticodon. In this case, the anticodon GGG on the tRNA pairs with the codon CCC on the mRNA and delivers the amino acid proline. The ribosome then forms a peptide bond between this amino acid and the next one, continuing the process until the entire protein is synthesized.
In summary, the DNA triplet GGG leads to the incorporation of proline in a protein by being transcribed into mRNA as CCC, then translated with the help of a tRNA anticodon GGG carrying proline. This illustrates the central dogma of molecular biology where DNA is transcribed into RNA, which is then translated into protein.
