Extended Data Table 6 Calculation of cross-bridge work from enthalpy efficiency

From: Remarkable muscles, remarkable locomotion in desert-dwelling wildebeest

  1. Data were based on a previous study19. a, Definitions of terms. b, Equations. c, Values for muscle from three species. Max ηCB and WCB were calculated from the equations in b using values of g and fA from table 11 of the previous study19. Wmax is 50 zJ, the theoretical maximum cross-bridge work per attachment cycle. d, Maximum enthalpy efficiency and work values for wildebeest muscle. εmax = 0.626 is the maximum enthalpy efficiency. ηCB and WCB were calculated using the equations in b. We assumed that our εmax from cyclic movement experiments also applies in isotonic or isovelocity experiments (see supporting evidence in Extended Data Table 5). The values of g and fA are all combinations of the values for dogfish white fibres, mouse EDL fibres and tortoise rectus femoris muscle (see table 11 of the previous study19). WCB/Wmax is the work actually done by the cross-bridge as a percentage of the theoretically maximum cross-bridge work. The highest and lowest values of WCB/Wmax are indicated in bold. e, Values for cow fibre bundles corresponding to those described in d.
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