The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.

DEFINITION:

calorie

Calorie (large c. or large calorie): The calorie used in metabolic studies, being the amount of heat required to raise the temperature of 1 kilogram of water 1 degree Celsius (centigrade), specifically from 14.5° to 15.5°C at a pressure of 1 atmosphere; abbreviated kg-cal. Called also kilocalorie. Also used to express the fuel or energy value of food.

calorie (small c.) - The amount of heat required to raise the temperature of 1 gram of water 1 degree Celsius (centigrade) specifically from 14.5° to 15.5°C at a pressure of 1 atmosphere; abbreviated g-cal. Called also gram c. and standard c.

The calorie used in chemistry and biochemistry is equal to exactly 4.184 joules. Symbol cal.

NOTE: There was formerly a distinction made between the "small calorie," defined above and the "large calorie" written Calorie with a capital "C" and abbreviated Cal, which was equal to 1000 small calories or one kilocalorie. The use of the large calorie survives only in nutrition, where calorie, now usually written with a small "c," means kilocalorie when specifying the energy content of foods.