Table 1.

Summary of K_m-values for sucrose uptake into SE/CCs or PPC obtained by non-linear least-square fitting (NLSF) using SIGMA PLOT 11.2 or Eadie–Hofstee transformation.

Sucrose-uptake parameters of the concentration-dependence of the sucrose-induced depolarizations were fitted to a Michaelis–Menten equation (MM) and the sum of two MMs (2 MM). K_m values were also obtained from the linear fittings of Eadie–Hofstee transformations (MM, 2 MM). Goodness-of-fit was evaluated from R² and SSR. A small SSR is indicative of a tight fit of the model to the data. Standard errors (SE) of the fitted parameters are given for the non-linear fittings.

^aN.d.: not determined. Given the distinct biphasic character of the EH transformation, a linear regression of the data points with only one K_m value is not appropriate.