Question

a) Explain what is meant by the statement “the genetic code is degenerate”. Why it is advantageous for the code to be degenerate?

b) How is it possible that some tRNA molecules recognize more than one codon?

Answer 1

a) Explain what is meant by the statement “the genetic code is degenerate”. Why it is advantageous for the code to be degenerate?

The phrase “the genetic code is degenerate” refers the instances in which different codons specify the same amino acid. It enable the genetic code to encode fewaminoacids encoded by more than one codon. Genetic codon degeneracy mostly occurs at third position.

The adavantages of degeneracy is that it minimize the mutation frequency that leads to non-functional aminoacids. Mutation leads to substituitionof codons causing mutation that could affect the  the functionality of the protein.

Studies also report that the degeneracy of the genetic code is important for organisms to prosper on Earth.

b) How is it possible that some tRNA molecules recognize more than one codon?

Transfer ribonucleic acid (tRNA) is one of the types of RNA that function to translate the genetic code of messenger RNA (mRNA) sequence into a protein. It base pairs with the mRNA codon on a sequence of 3 bases called anticodon. Some tRNA recognize more than one codon is evident from the fact that the number of different tRNAs for each amino acid is not the same as the number of its codons.

Well... Human physiology is full of surprises!

A phenomenon called wobble enable abnormal base pairing between nuclotides except A-U and G-C—can form at the third position of the codon

Normal rules arenot meant for wobble pairing. As an example, G in the anticodon can pair with either C or U but not an A or G. Wobble pairing also ensures that the codons are read in correcct way despite wobble. This makes possible for fewer tRNAs to cover all the codons of the genetic code with the also with assurity that the code is read accurately.