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  Home > JCE Print > Journal of Chemical Education > Issues > 1998  > March  >
Chemistry Everyday for Everyone
Tested Demonstrations
Detection of Catalysis by Taste
Robert M. Richman
Mount St. Mary's College, Department of Science, Emmitsburg, MD 21727-7799
Cover
March 1998
Vol. 75 No. 3
p. 315
Abstract
A classroom demonstration is outlined to illustrate by taste the large effect that a small quantity of catalyst can have. The enzyme lactase, obtained from the over-the-counter product Lactaid, catalyzes the hydrolysis of the disaccharide lactose into D-glucose and D-galactose, its monosaccharide constituents. These products have a combined sweetening power of about 0.8 relative to sucrose. The sweetness can be easily discerned in milk that has been treated with Lactaid. It is readily apparent that the Lactaid itself is not the source of sweetness, since it is a rather tasteless substance that is diluted in milk by a factor of roughly 4000 to 1. It is estimated that each lactase molecule hydrolyzes 105 lactose molecules.
More Information
*  Citation
 Richman, Robert M. J. Chem. Educ. 1998 75 315.
*  Keywords
 Demonstrations, Catalysis, Enzymes, Food Science, Biochemistry
*  History
 Created:
Last Updated:		 June 28, 1999
June 23, 2005
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