Which component is essential for the synthesis of proteins in cells?

The correct choice highlights RNA as essential for protein synthesis in cells. During protein synthesis, the process begins with DNA, which serves as a template for transcription. In this process, messenger RNA (mRNA) is synthesized from the DNA sequence. This mRNA then travels from the nucleus to the ribosomes in the cytoplasm, where it serves as the blueprint for assembling amino acids into proteins through the process of translation.

Ribosomal RNA (rRNA) and transfer RNA (tRNA) also play fundamental roles in translating the mRNA sequence into a polypeptide chain. rRNA forms the core of the ribosome's structure and its catalytic activity, while tRNA brings the appropriate amino acids to the ribosome as specified by the mRNA.

While DNA is crucial for storing genetic information and ATP is important for energy supply, and glucose serves as an energy source, it is RNA that directly participates in the synthesis of proteins. Without RNA, the instructions encoded in DNA could not be effectively translated into the functional proteins necessary for cellular functions.