Zinc Channel (image) Johns Hopkins Medicine Caption The twisting (blue arrows) of the red portion of the zinc ion channel allows the opening and closing of its gate. Left: the channel is open to the inside of the cell, allowing zinc (green) to flow into its binding site (pink star) after hydrogen flows out. Right: the channel is open to the outside of the cell, allowing zinc to flow out and hydrogen to flow in. Credit Fu Lab, Johns Hopkins Medicine Usage Restrictions Credit required. Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.