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 Carbohydrates (also called saccharides) are molecular compounds made from just three elements: carbon, hydrogen and oxygen. Monosaccharides (e.g. glucose) and disaccharides (e.g. sucrose) are relatively small molecules. They are often called sugars.Other carbohydrate molecules are very large (polysaccharides such as starch and cellulose). Carbohydrates are: 1  a source of energy for the body e.g. glucose and a store of energy, e.g. starch in plants.2  building blocks for polysaccharides (giant carbohydrates), e.g. cellulose in plants and glycogen in the human body.ther carbohydrate molecules are very large (polysaccharides such as starch and cellulose). Carbohydrates are: 1  a source of energy for the body e.g. glucose and a store of energy, e.g. starch in plants. 2  building blocks for polysaccharides (giant carbohydrates), e.g. cellulose in plants and glycogen in the human body.