Pharmaceutical Chemistry

Na+/K+ pump and Photosystems

The Na+/K+ pumping between inside and outside a cell is assisted by a membrane-bound Na+/K+ - ATPase enzyme that catalyzes the movement of ions in the both direction across a cell. Through this pumping process the concentration difference of the ions inside and outside a cell is maintained and hence, a constant cell potential achieved. The activity of this pump is estimated to account for 20–40% of the brain's energy consumption, indicating its importance for brain function. The Na⁺ pump was first discovered in neurons in the 1950s, when Richard Keynes at Cambridge University used radioactive Na⁺ to demonstrate the energy-dependent efflux of Na⁺ from squid giant axons.