Abstract
Summary
Oxygen consumption and carbon dioxide elimination in Pelomyxa caro-linensis was ascertained by means of a Bar-croft-Warburg micro-respirometer. The total average oxygen consumption was found to be 2442 mm 3 , SS94 mm 3 , 11,664 mm 3 and 26,971 mm 3 per hour per million organisms (or 0.07, 0.16, 0.33, and 0.76 mm 3 per hour per cubic millimeter cell substance) at 10°, 20°, 30°, and 35°C., respectively.
The respiratory quotient varies directly with the temperature. It was found to be 0.45 at 10°C and 0.94 at 30°C. Consequently, carbohydrate metabolism is evidently greater at higher than at lower temperatures.
Respiration is inhibited by potassium cyanide ( 10 - 4 M) and the degree of inhibition varies directly with the temperature.
From the evidence presented, it can be concluded that a cytochrome-cytochrome oxidase system is the mechanism chiefly involved in oxidation of carbohydrate in Pelomyxa and that as carbohydrate metabolism is reduced in its extent, this mechanism becomes less and less active.
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