In general, foods are made up of carbohydrates, proteins, and fats, each of which provide a different number of calories: 1  Carbohydrates provide 4 calories per gram. 2  Proteins provide 4 calories per gram. 3  Fats provide 9 calories per gram.
Importance of Water. Water is used for various important purposes: Water in Agriculture. Water plays the most important role in agriculture. Agriculture is impossible without irrigation throughout the crop season. Irrigation ensures proper plant growth.
The Importance of Water and its Properties for Living Organisms. Next to oxygen, water is essential for all living organisms on Earth. It is a major component in cells, which make up all living organisms; therefore approximately 60% to 95% of living organisms are water.