| Comments |
P.423 right column bottom paragraph: "Model version II features a 1 Ca2+/2 H+ exchange and an active CO2 import into the CV [coccolith vesicle]. The resulting pH of 10.6 (Table 4) is high, but can be lowered when further increasing the import rate of CO2: An elevation of Vmax(CO2) from 1.4 fmol · s^−1 to 16 fmol · s^−1 leads to a pH of about 9 and a [CO2] of 52 mmol · L^−1. The Vmax(CO2) listed in Table 4 (gross value) is actually already 350-fold higher than the net Vmax(CO2) given by Schulz et al. (2007). The gross Vmax(CO2), however, has not been determined. Concerning the high [CO2], maximum rates for the diffusive CO2 efflux from the CV will certainly be induced. A considerable CO2 leakage, however, is a well-known phenomenon in algae (Kranz et al. 2009)." |