These structures have been installed and operated for a number of reasons: 1  locks allow navigation on large rivers to facilitate boating traffic. 2  weirs create pool environments for diversion into irrigation channels, for pump intakes, recreational boating and swimming, and other aesthetic reasons.
Medical Definition of carbohydrate. : any of various neutral compounds of carbon, hydrogen, and oxygen (as sugars, starches, and celluloses) most of which are formed by green plants and which constitute a major class of animal foods.
Carbohydrates: The Monosaccharides. The term carbohydrate was originally used to describe compounds that were literally hydrates of carbon because they had the empirical formula CH 2 O. In recent years, carbohydrates have been classified on the basis of their structures, not their formulas.