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.
Importance of safe drinking water. 4.1 A safe, clean, and reliable supply of drinking water is critical to public health. In many parts of the world, drinking water is still untreated and carries water-borne diseases causing human illnesses and death.