Kaplan Nursing Entrance Practice Exam

What is the primary function of mRNA?

1. Store genetic information

2. Encode gene messages to form proteins

3. Assist in protein synthesis

4. Transport amino acids to ribosomes

The correct answer is: Encode gene messages to form proteins

The primary function of mRNA, or messenger RNA, is to encode gene messages that direct the synthesis of proteins. This process begins in the nucleus of a cell, where DNA is transcribed into mRNA. The mRNA then carries the encoded information from the DNA to the ribosomes, the cellular machinery responsible for protein synthesis. Once at the ribosome, the mRNA is read in sets of three nucleotides, called codons, each of which corresponds to a specific amino acid. This translates the genetic code into a functional protein, highlighting the central role mRNA plays in gene expression and protein production. In contrast, other functions mentioned, such as storing genetic information, are primarily the role of DNA, while protein synthesis also involves tRNA, which transports amino acids, and ribosomal RNA (rRNA), which contributes to ribosome structure and function. Thus, while those elements are essential in the overall process of protein synthesis, mRNA's specific role is as the messenger that carries the instructions for assembling amino acids into proteins.