Fig. 5. Kinetics of frog mitochondrial oxygen consumption rates in the low oxygen range at 3 °C for hypoxic submerged frogs. The kinetics for state 3 (A) and state 4 (B) respiration are shown. Solid line, control; dashed line, 1-month-submerged; dotted line, 4-month-submerged groups of frogs. The insets show how P₅₀ was calculated for each group of frogs. These curves were generated using the equation _O2=100[P_O2/(P₅₀+P_O2)], where _O2 (as a percentage of maximum) is the rate of oxygen consumption for state 3 or state 4. The state 3 and state 4 values from the control group of frogs were set to 100%, and those for the 1- and 4- month-submerged groups of frogs were expressed relative to the controls. To convert PO₂ to µmol, kPa must be multiplied by a factor of 11.3 and mmHg by a factor of 1.5. To convert kPa to mmHg, kPa must be multiplied by a factor of 7.51. From St-Pierre et al. (2000c) with permission.