Carter Clock (IMAGE) University of North Carolina Health Care Caption Escapement mechanisms of clocks as a metaphor for protein function like Maxwell's demons. The Foliot swings back and forth like the pendulum in a clock. The essential features enabling time keeping are labeled. The central function of an escapement is illustrated by the two dark green blades that control the advance of the crown gear in a mechanical clock. Credit Carter, UNC School of Medicine Usage Restrictions None License Licensed content 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.