MODEL EXPERIMENT ON THE CONTRACTION OF MUSCLE FIBER

Abstract

So many reports have been published on the contraction of muscle fiber, and the role of ATP upon the contraction of myosin fiber became to be known quite well. But the myosin fiber contracts under various conditions inclusive of the action of ATP. And the mechanism by which the shortening of myosin fiber or other contractile substances is evoked is not known yet in detail.The authors in this work demonstrated the change of configuration and the movement of mercury particles as a model of muscle contraction or the movement of monocellular microorganism.The experiment is as follows. Resting particles of mercury in K2Cr2O7 solution began to move to and fro changeing into cubic or spindly shaped, when small amount of HNO3 was poured into the K2Cr2O7 solution. The reason is that the surface tention of mercury in K2Cr2O7 solution is small and its shape flat and prolonged because the particles are coated with oxide membrane in K2Cr2O7 solution alone, but when HNO3 was added the surface membrane of mercury was destoryed and the surface tention becomes great, resulting in the contraction and the movement.