Question

How do you read a codon table?

Answer 1

Hint: A codon is a triplet code which determines which amino acid is to be synthesised. The codon has three alphabets which stands for the amino acid. The first codon read by mRNA is a start codon and the translation stops after reading stop codons.

Complete answer:
 During protein synthesis, the DNA is transcribed into mRNA and mRNA translates into amino acids. The mRNA formed in the nucleus carries a code which consist of three nucleotides. The nucleotides that are present in DNA and RNA are Adenine(A), Guanine (G). cytosine (C), Thymine (T), uracil (U). This triplet code specify the amino acid to be formed. The translation begins with the start codon AUG which codes for methionine and stops when it carries the message UAA, UAG, UGA which do not code for any amino acid and are nonsense codons.

These codons are read from the start codon in the 5’ to 3’ direction. This specifies the order of the amino acid from N-terminus to C terminus. The codon table is a table which shows the way a triplet codon is read by the tRNA so as to map an amino acid.

The codon table is shown below:

From the table, we can find out which sequence of mRNA will be read for which amino acid. For example, ACU will code for threonine.

Note: There are 64 codons for 20 amino acids. These codons are universal as they are similar for all kinds of organisms. The essential amino acids are not produced in our bodies. They are to be taken through food.