What is the primary function of ribonucleic acid (RNA) in cells?

• A. To store genetic information
• B. To synthesize proteins
• C. To catalyze biochemical reactions
• D. To replicate DNA

Answer: (B)

The primary function of ribonucleic acid (RNA) in cells is to synthesize proteins. RNA serves as a crucial intermediary between the genetic information stored in DNA and the production of proteins, which are essential for cellular function and structure. During the process of transcription, messenger RNA (mRNA) is synthesized from a DNA template, carrying the genetic code from the nucleus to the ribosomes where protein synthesis occurs.

At the ribosomes, mRNA is translated into a specific sequence of amino acids, creating proteins. This process involves transfer RNA (tRNA), which brings the correct amino acids to the ribosome, and ribosomal RNA (rRNA), which is a component of the ribosome itself and helps facilitate the translation process. This role of RNA in protein synthesis highlights its importance in expressing the genetic information contained in DNA and is central to cellular function.

The other options represent functions that are either not performed by RNA or are not its primary role. For instance, while RNA plays a role in some catalyzing processes (as seen in ribozymes), protein synthesis is its most fundamental and essential function.