NEET BIOLOGY

Detailed explanation-1: -Codons in an mRNA are read during translation, beginning with a start codon and continuing until a stop codon is reached. mRNA codons are read from 5’ to 3’, and they specify the order of amino acids in a protein from N-terminus (methionine) to C-terminus.

Detailed explanation-2: -The three-letter nature of codons means that the four nucleotides found in mRNA-A, U, G, and C-can produce a total of 64 different combinations. Of these 64 codons, 61 represent amino acids, and the remaining three represent stop signals, which trigger the end of protein synthesis.

Detailed explanation-3: -This process is repeated until all the codons in the mRNA have been read by tRNA molecules, and the amino acids attached to the tRNAs have been linked together in the growing polypeptide chain in the appropriate order.

Detailed explanation-4: -The tRNA is located in the ribosome’s first docking site. This tRNA’s anticodon is complementary to the mRNA’s initiation codon, where translation starts. The tRNA carries the amino acid that corresponds to that codon. The next mRNA codon is now exposed in the ribosome’s other docking site.