We are referring to the number of RUBISCO active sites measured by immunoquantitation. We are not referring to measured RUBISCO activity. We use this expression to be clear that we are referring to RbcL subunits rather than oligomeric RUBISCO. We have added a parenthetic phrase to make this more clear.
Round 1: and Author Response The authors present a dataset where they have characterised the relative abundance of components of the photosynthetic electron transfer chain and related this to the measured rate of electron transfer from PSII.