Question

Which site of a tRNA molecule forms hydrogen bonds with mRNA?

A) Codon

B) Anticodon

C) 5’ end of the tRNA

D) 3’ end of the tRNA

Answer 1

Hint: tRNA is composed of three nucleotides. Each tRNA can be bound to specific mRNA. The tRNA molecule brings an amino acid, particularly, the one encoded by the codons binding the tRNA.

Complete answer:

To solve this question, first we should know the function of tRNA and mRNA. A special type of RNA molecule is a transfer RNA (tRNA). tRNA brings the amino acid to a ribosome as guided by a 3-nucleotide sequence in the mRNA. The unique nucleotide sequence of an mRNA determines the amino acids are inserted into the protein product of the gene from which the mRNA is transcribed; the function of tRNA is to determine which genetic code sequence relates to which amino acid.

tRANsact at particular sites in the ribosome throughout the translation, which is a mechanism that synthesizes the protein from the mRNA molecule. The role of tRNA is to read the message of nucleic acids, or nucleotides, and to convert it into proteins or amino acids.  

Now lets us find the solution from the given options-

- mRNA comprises codons complementing nucleotide sequences on the DNA template and directing amino acid production by the action of ribosomes and tRNA. So, codon cannot be the correct answer. Thus, option A is the incorrect option.

- Hydrogen bonds bind the complementary bases on codon and anticodon together. Codon is found on the mRNA, and there is anticodon on the tRNA. On mRNA, codon forms hydrogen bonds with a tRNA anticodon site. The ribosome enables tRNA to be bound to the mRNA bearing a particular amino acid.

- The 5 'end of the RNA molecule has a reactive group of phosphates bound to the 5th ribose carbon atom. It occurs in the 5 'and 3' ends of the RNA when the other groups of phosphate and hydroxyl are involved in nucleic acid phosphodiester bonds.  So, 5 'end of the RNA cannot be the correct answer. Thus, the option C is the incorrect option. 

- The third carbon atom has a free hydroxyl bond on the 3 ' end of the t-RNA molecule which is included in phosphodiester bonds within the nucleic acid. 

So, 3 'end of the RNA cannot be the correct answer. 

Thus, the right option is option (B) i.e. Anticodon.

Note: A tRNA can be categorized according to the amino acid it bears, resulting in 20 different tRNA. They may also be categorized based on their anticodon. A combination of four nucleotides makes up 64 codons. Of these, three are stop codons signaling the end of translation.