Classified List of Publications of the Carnegie Institution of Washington Volume 187 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1913 Excerpt: ...fat disintegration. In opposition to this theory, Zuntz cites experiments made by his various students, especially those of Frentzel and Reach" and also the experiments of Atwater, Sherman, and Carpenter,6 which showed that the absorption of oxygen per unit of work is essentially the same whether fat or carbohydrate is burned. According to Zuntz, therefore, there is no selective combustion of carbohydrate material during muscular activity; furthermore, since Chauveau's theory would require for a unit of external muscular work 30 per cent more energy with fat than with carbohydrates, Zuntz argues that all nutrients can furnish muscular energy without previous transformation into sugar." Respiratory Quotients Of Bicycle Ergometer Experiments And Their Significance. A comparison of the character of the katabolism before, during, and after work may be made either directly by comparing the respiratory quotients, or by comparing the amounts of protein, fat, and carbohydrates katabolized per minute, as computed by the Zuntz formula from the measurements of the nitrogen and carbon-dioxide output and the oxygen consumption. Since the character of the katabolism has a direct influence upon the relation between the carbon-dioxide excretion and the oxygen consumption, we have considered it unnecessary to make the elaborate computation of the amounts of glycogen and fat katabolized per minute, and have based all our comparisons upon the respiratory quotient. In doing this we have assumed that low respiratory quotients indicate a katabolism chiefly of fat and protein, and that the higher the quotient the greater the proportion of carbohydrates burned. It has, furthermore, been assumed that throughout the rest and work periods there is a relative constancy in th...