Long distance cell-to-cell or organism-to-organism communications may be accomplished by transmission and reception of electromagnetic signals through membrane receptors or enzymes. Consistent with this idea is the observation that membrane ATPases are capable of absorbing energy from oscillating electric fields of defined frequency and amplitude and using it to perform chemical work. The concept of the 'electroconformational coupling' is used to explain how an electric signal can modulate the activity of a membrane protein, and conversely, how an energy-dissipating reaction can produce an electric signal.