Abstract
The respiration of the green alga Chlorella pyrenoidosa, suspended in Knop's solution, has been studied in the dark as a function of time and of temperature. The rates of oxygen consumption and of carbon dioxide production (at constant temperature) decline for about 25 hours to a low, constant level. From an analysis of the curves it is suggested that two substances, A and B, are utilized, whose respiratory quotients are 1 and 0.65 respectively. The values of the temperature characteristics were found to be: for oxidation of A, 19,500 (0.6 to 11.5 degrees C.) and 3,500 (11.5 to 28 degrees C.); for oxidation of B, 5,600 (23.4 to 0.6 degrees C.).