Isometric tension exerted by a myofibril of the frog at 0 degree C: geometrical considerations.
For a number of years, the isometric force per myosin head has been taken as 1 pN by the authors who studied in vitro movement. This value was deduced from the value of the isometric tension exerted by a living or a skinned fibre at approximately 0 degree C and for the frog (1-3 kg cm-2). Starting from an isometric tension exerted by a single unit cell of approximately 10 kg cm-2, it has been shown that the isometric force per myosin head is (8 +/- 1)pN. The value of approximately 10 kg cm-2 was deduced from theoretical and semi-empirical reasonings independent of the mechanical roles of the crossbridges. Here, we discuss this latest value by using simple geometrical considerations.
Merah
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D000818:Animals; D001001:Anura / Q000502:physiology*; D003080:Cold Temperature; D007537:Isometric Contraction / Q000502:physiology*; D008433:Mathematics; D009132:Muscles / Q000502:physiology* / Q000648:ultrastructure; D013696:Temperature