Question

If following is the sequence of nucleotide in mRNA, predict the sequence of amino acid coded by it :
AUG UUU UUC UUC UUU UUU UUC
Can you now correlate which two properties of genetic code you have learned?

Answer 1

Hint: Genetic codes exist in the form of triplets and each code for a unique amino acid. AUG is also known as a start codon and codes for a sulfur-containing amino acid. UUU and UUC code for a hydrophobic and aromatic amino acid, having a benzene ring in its structure.

Complete answer:
The sequence of nucleotide in the given mRNA is-
Methionine Phenylalanine Phenylalanine Phenylalanine Phenylalanine Phenylalanine Phenylalanine
The two properties genetic code shown in the above sequence are-
-Redundant
-The genetic code is redundant or degenerate means each codon corresponds to a single amino acid but a single amino acid can have multiple codons.
-example –UUU and UUC both codes for Phenylalanine
-Non- overlapping and non-punctuated
-The codon is read in triplet continuous from left to right means three-nucleotide base form one amino acid with the use of the comma.
-Each codon consists of three bases i.e. triplet. Therefore, there are 64 codons out of which 61 codon codes for 20 amino acids and 3 codons don't code for any amino acid.
-The sequence of DNA has thiamine in the codon and the sequence of RNA has uracil in the codon.

Additional Information:
 -Genetic code was given by Goerge Gamow.
-The genetic codon consists of a signal codon that starts codon and stops codon.
-Universal
-The genetic codon is universal, which means the same genetic code is valid for all the organisms.
Specificity
- Genetic code is specific or unambiguous which means a specific codon always codes for the same amino acid.
-AUG- methionine
UUU- Phenylalanine
UUC- Phenylalanine

Note:
 -There are three stop codons or nonsense codons- UAG, UAA, and UGA.
-In eukaryotes, the start codon is always AUG with codes for methionine where in prokaryotes it codes for formylmethionine or modified methionine.
-The Crick, Brenner, Barnett, and Watts- Tobin experiment for the first time demonstrated that codon consists of three DNA bases.