Ribosomes are structures where messenger RNA (mRNA) is translated to a corresponding sequence of amino acids, forming a peptide chain. A “protein” is, generally speaking, a molecule that can refer to sufficiently long peptide chains (called polypeptides) and/or a composite of multiple polypeptides that are held together by intermolecular forces in a specific conformation. Therefore, a cell that has many functional ribosomes is probably engaged in very active protein production.