Which structure is responsible for protein synthesis?

Ribosomes are the cellular structures that are directly responsible for protein synthesis. They serve as the site where messenger RNA (mRNA) is translated into polypeptide chains, which then fold to form functional proteins. During this process, ribosomes read the sequence of codons on the mRNA and, using transfer RNA (tRNA), they assemble amino acids in the correct order to create proteins. This function is crucial for the cell because proteins play a vital role in numerous biological processes, including structural roles, enzyme activity, and cell signaling.

In contrast, fats and electrolytes do not participate directly in protein synthesis. Fats primarily serve as energy sources and structural components of cell membranes, while electrolytes are essential for maintaining the balance of fluids and electrical charges in the body. DNA, while inherently related to the production of proteins as it contains the genetic instructions for making them, does not participate directly in the synthesis process itself. Instead, it provides the template from which mRNA is transcribed, which is then utilized by ribosomes for protein assembly. Thus, ribosomes are the key players in the actual synthesis of proteins within the cell.