Abstract During the last two decades, zinc has been shown to be a functionally essential component of more than 120 enzymes and concurrently has been recognized as indispensible to normal cellular growth, development and differentiation of all species. However, the manner in which it exerts its effects are still unknown. Studies of the phytid E. gracilis have demonstrated that zinc is critical for transcription and translation, affecting the metabolism of RNA polymerases, mRNA and proteins, among which are histones and arginine-containing peptides. These and other data lead to the suggestion that this element has a fundamental role in gene activation and/or repression, accounting for its pervasive effects on cell metabolism.