Question

Which one of the following triplet codes, is correctly matched with its specificity for amino acid in protein synthesis or as ‘start’ or ‘stop’ codon?
(A) UAC-Tyrosine
(B) UCG-Start
(C) UUU-Stop
(D) UGU-Leucine

Answer 1

Hint: The genetic code is referred to as degenerate or redundant since a single amino acid may be coded for by more than one codon, despite the fact that each codon is specific for just one amino acid. A genetic code is clear and specific since each codon only codes for one amino acid.

Complete Step by Step Answer:
In biology, a codon is the fundamental genetic building block of life that serves as the blueprint for the amino acid synthesis necessary for protein expression. The expression of proteins is the method by which the information contained on genes is expressed. Genes contain all the information necessary for life. The first codon in the transcribed mRNA to undergo translation is the codon AUG, which is why it is known as the START codon. The most prevalent START codon, AUG, codes for the amino acids methionine (Met) and formyl methionine (fMet) in eukaryotes and prokaryotes, respectively. A stop codon is a nucleotide sequence of three nucleotides found on mRNA that tells the cell to stop the production of proteins. There are 64 distinct trinucleotide codons, of which 3 are stop codons and 61 define amino acids (i.e., UAA, UAG and UGA).
Proteins contain codons, which are triplets of the nucleotide bases that designate a specific amino acid. Cease codons are the codons that actually stop the production of proteins. UAG, UAA, and UGA are RNA stop codons. The start codon designates the first codon of an mRNA transcript that a ribosome translates. In prokaryotes and eukaryotes, it codes for a modified form of Met. The most frequent start codon is "AUG." Serine is coded by UCG, phenylalanine by UUU, cysteine by UGU, and tyrosine by UAC.
So, option (A) is the correct answer.

Note: The start codon designates the beginning of translation into a protein sequence, and the stop codon designates the end of translation. As stop codons do not encode for any amino acid but rather mark the end of the process of protein synthesis that is translation, they are also known as nonsense codons.