Question

Identify the mismatched one
A. CUU-Leucine
B. GGU- Glycine
C. GCU- Alanine
D. GAA- Valine

Answer 1

Hint:- The codons are the base pairs present in such a way that they code for a particular amino acid only. They are present as a triplet and are only read in a particular reading frame. They are very specific. They code for a specific protein formation.

Complete answer:
The codons consist of the genetic sequence which has three nucleotides present. they code for a particular amino acid only and are very specific. The codons that code for leucine are UUA, UUG, CUU, CUC, CUA and CUG. The glycine is coded by GGU, GGC, GGA and GGG. Alanine is coded by GCU, GCC, GCA and GCG. Valine is coded by the GUU, GUC, GUA and GUG. There is the presence of start codon which helps in the regulation of translation. The start codon is AUG which also codes for methionine. There are stop codons which stop the translation to occur. They are UAA, UAG and UGA. These stop codons don’t code for any amino acid and are present only to stop the further translation. The codons consist of the four base pairs which have to code for 20 amino acids. So, a combination of 64 codons is formed to code for these amino acids. These codons are specific and unambiguous which means that each codon will code for a particular amino acid only. They have the property of degeneracy which means that an amino acid can be coded by many codons and not only a particular codon. They are read continuously, deletion or addition of a base pair can change the reading frame from that point.

So, the answer is GAA- Valine, option (D).

Note:- The codons are universal which means that for all the organisms the same codon will code for the same amino acid. Only the start codon AUG has two functions to perform which are to start the translation and to code for methionine.