Assuming there were 20 different amino acids and less than 40 types of different tRNAs found in this alien organism. How many amino acids would be found in the translational product of a 600-nucleotide mRNA?
I am very confused over how I should solve this question.
If we assume 1 codon = 1 nucleotide,
20 amino acids require 20 different codons = 20 different nucleotides < 40 different tRNAs.
If we assume 1 codon = 2 nucleotides,
20 amino acids require 20 different codons = 5 x 5 combination of nucleotides? (considering A, T, C, G, U)?
5 x 5 = 25 < 40 different tRNAs.
The correct answer is to consider 1 codon = 2 nucleotides.
My question,
Since both 1 codon = 1 nucleotide and 1 codon = 2 nucleotides fit the requirement of this question, why is 1 codon = 2 nucleotides the correct answer?