Question

In which of the following ways are tRNA and mRNA different?

a. The mRNA repairs mistakes in the DNA while tRNA repairs proteins.
b. Only tRNA bends into a shape that can carry specific amino acids.
c. Only tRNA can come in contact with the ribosomes in the cytoplasm.
d. The mRNA uses uracil while the tRNA uses thymine in its place.

Answer 1

tRNA and mRNA differ in their functions in protein synthesis, where tRNA carries specific amino acids to the ribosome and mRNA carries the codon sequence that dictates the order of amino acids. It is the 3D structure of tRNA that allows it to perform its role; both tRNA and mRNA use uracil, not thymine.

Step-by-step explanation:

The differences between tRNA (transfer RNA) and mRNA (messenger RNA) are significant in the process of protein synthesis. The correct answer to the question is option b. Only tRNA bends into a specific three-dimensional structure that enables it to carry specific amino acids to the ribosome during protein synthesis. mRNA, on the other hand, is a single-stranded transcript of DNA that carries the genetic code for a protein which is read in sets of three bases called codons, where each codon corresponds to one amino acid.

Moreover, tRNA molecules have anticodons that pair with the codons on the mRNA strand, thus ensuring the insertion of the correct amino acid into the growing polypeptide chain. mRNA does not have amino acid-carrying capacity. Unlike mRNA, tRNA is not involved in carrying the genetic instructions directly from DNA; instead, it plays a crucial role in translating mRNA’s codons into the amino acid sequence of proteins.

It is also important to note that both mRNA and tRNA, like all types of RNA, use uracil instead of thymine. Therefore, the statement in option d, which claims that tRNA uses thymine, is incorrect as thymine is found in DNA, not RNA.

Answer 2

The correct option is C.
The tRNA is the only type of RNA that can come in contact with the ribosomes in the cytoplasm. During the translation process of protein synthesis in the cell, the tRNA function by carrying amino acid to the ribosomes and matching the codon in the mRNA with the amino acid it codes for. Thus it acts as a bridge between mRNA and ribosomes.