How does the cell choose which amino acid to attach to tRNA when there is wobble base pairing involved (not the other way around)? Consider the example below.

For the purpose of this question I'm picking UGC, UGA and UGG codons (Cys, Stop and Trp aa's) so that the 3rd position of the codon really makes a difference (if it does).

I know there are other pairings out there but to keep it really simple for myself I derived the following tRNA anticodons to match the codons using these rules: G pairs with C or U, C pairs with G, U pairs with A or G, A pairs with U, I pairs with A, U or C.

UGC: ACG or ACI anticodons

UGA: ACU or ACI anticodons

UGG: ACU or ACC anticodons

My question is (assuming I did my work correctly) if there are multiple possibilities for anticodons to match with each codon how would we know which amino acid will attach to which anticodon? Take for example the ACU anticodon that could potentially match with UGA or UGG codons which codes for STOP or Trp. Wouldn't there be a discrepancy/confusion on which to code for by the cell? Ultimately wouldn't this affect the peptide/protein synthesized?

NB I have edited the original question to clarify my problem, which I do not think is answered elsewhere.

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    $\begingroup$ Possible duplicate of Redundancy of the genetic code $\endgroup$
    – David
    May 16, 2019 at 8:32
  • $\begingroup$ Welcome to SE Biology. As you will see, your question has been answered before (by me, among others). You may also be interested in the situation in mitochondria where the wobble rules are different because of the different tRNA structures. See may answer here. $\endgroup$
    – David
    May 16, 2019 at 8:38
  • $\begingroup$ It may be irksome to post a detailed question and be told that it is answered elsewhere. However if you feel that it has not been answered, the solution is not to complain in the title, nor is it any way relevant to cast aspersions on answers to other questions. The latter course of action is likely to lead to the moderators deleting your question. People are trying to help without unnecessary duplication. What you should do is reply to the comment, in a comment, and expand your question as necessary. I have edited your question and will address your clarification in a second comment. $\endgroup$
    – David
    May 24, 2019 at 21:16
  • $\begingroup$ You ask “How does the cell choose which amino acid to attach to tRNA?” It sounds as if you are unfamiliar with the family of amino acyl tRNA-synthetase enzymes and their specificity for cognate tRNAs? If so, please read the section in Berg et al. on line. If this does not answer your problem, please explain why not. $\endgroup$
    – David
    May 24, 2019 at 21:22


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