Abstract
Since the time of pioneer work of Lavoisier in 18th century, calorimetry have been one of the fundamental approaches in the study of bioenergetics. A review of the historical background of the calorimetric investigations in the field of bioenergetics was briefly described. Our recent construction of a twin-type microcalorimeter equipped with rapid response microthermistors and oxygen electrode, which allows simultaneous recording of heat production and oxygen consumption in a small volume (5cm3) of biochemical reaction systems, was introduced. Performance of the apparatus was tested with acid base neutralization reaction and some enzymatic reactions. Results from the measurements of the energy balance in the energy transducing reactions of rat liver mitochondria under various respiratory states were described with special interest on the mechanism and control of heat production in mitochondria by long chain unsaturated fatty acids.
