Questions

If the gene for the second tRNA (the one whose anticodon normally recognizes the arginine codons AGG and AGA) were non-functional, the cell would no longer be able to efficiently incorporate arginine at positions in proteins where AGG or AGA appear. Here’s what would likely happen:

1. Inefficient Translation of Specific Codons:
   mRNAs that include AGG or AGA codons would experience ribosomal stalling or delays because no tRNA would be available to match these codons. This delay can slow overall protein synthesis.

2. Truncated or Misfolded Proteins:
   The stalled ribosomes might eventually lead to premature termination or misincorporation of amino acids if the ribosome “skips” the problematic codon. As a result, proteins containing these codons could be truncated or misfolded, potentially losing their proper function.

3. Altered Protein Expression:
   Genes that frequently use the AGG/AGA codons would be most affected, possibly leading to a reduced amount of functional protein. In contrast, genes using the other arginine codons (the CGX group) would remain unaffected, which might alter the balance of protein production in the cell.

4. Overall Cellular Impact:
   The deficiency in synthesizing correctly folded and complete proteins could compromise cellular processes. Depending on the role of the affected proteins, this might result in slower cell growth, stress responses, or even cell death if critical proteins are not properly produced.

The loss of the second tRNA gene would disrupt normal protein translation for those arginine codons (AGG and AGA), potentially leading to a cascade of cellular dysfunctions.