6O2 



PHYSIOLOGICAL CHEMISTRY 



This experiment may be made more complete by making determinations of 

 blood sugar at short intervals as described in Experiment 10, page 598. If 

 desired^ data on glycosuria, hyperglycemia and carbohydrate in feces (page 624) 

 may be collected from one experiment. 



13. Absorption of Carbohydrate as Influenced by Fat Ingestion. When fat is 

 eaten along with carbohydrate food the absorption of the latter is somewhat 

 delayed. This has been shown experimentally. 1 To demonstrate the point pro- 

 ceed as follows: Determine the content of sugar in the blood at various intervals 

 after the ingestion of 170 grams of white bread as described in Experiment ro (b), 

 page 599. Plot a curve for these values similar to the one shown in Fig. 188, page 

 599. On a later day repeat the experiment and ingest 170 grams of white bread and 

 85 grams of butter. Plot the curve for these blood sugar concentrations along with 

 blood sugar values obtained after the ingestion of white bread as described above. 

 Has the fat exerted any influence upon the absorption of the carbohydrate? Re- 

 peat the above experiment on a case of diabetes mellitus if such is available and 

 note that fat exerts the same influence upon carbohydrate absorption as it exerts in 

 the normal human body. 



14. Time Relations of Protein Metabolism. It is a well-known 

 physiological fact that an interval elapses between the ingestion of protein 

 food and the appearance in the urine of certain products representing the 

 complete catabolism of this food. For example, if one ingests an excess 

 of protein material an interval elapses before the urine gives evidence 

 of the complete excretion of certain products representative of the 

 catabolism of the protein. Urea is the chief of these. The term "nitro- 

 gen lag" has been used to designate the period elapsing between the 

 ingestion of protein and the excretion in the urine of a quantity of 

 nitrogen equivalent to that contained in the protein. 



Experiment. Ingest a simple uniform diet whose exact composition has been 

 determined by analysis or whose approximate composition has been estimated. 



COMPOSITION OF COMMON FOODS' 



1 Jacobson: Bioch. Zeit., 56, 471, 1913. 



1 Sherman's "Food Products," Macmillan, 1914. 



