NUTRITION

A nutrient is a component in foods that an organism uses to survive and grow. Macronutrients provide the bulk energy an organism's metabolic system needs to function while micronutrients provide the necessary cofactors for metabolism to be carried out. Both types of nutrients can be acquired from the environment. Micronutrients are used to build and repair tissues and to regulate body processes while macronutrients are converted to, and used for, energy. Methods of nutrient intake are different for plants and animals. Plants take in nutrients directly from the soil through their roots and from the atmosphere through their leaves. Animals and protists have specialized digestive systems that work to break down macronutrients for energy and utilize micronutrients for both metabolism and anabolism (constructive synthesis) in the body.

Organic nutrients consist of carbohydrates, fats, proteins and vitamins. Inorganic chemical compounds such as dietary minerals, water, and oxygen may also be considered nutrients. A nutrient is considered essential if it must be obtained from an external source either because the organism cannot synthesize it or because insufficient quantities are produced. Nutrients needed in very small amounts are called micronutrients while those needed in large quantities are called macronutrients. 

  Types of nutrient

    The chemical elements humans consume in the largest            quantities   

   The classes of chemical compounds humans consume in      the largest quantities and which provide bulk energy are          carbohydrates, proteins, and fats. Water and atmospheric        oxygen also must be consumed in large quantities, but are      not always considered "food" or "nutrients".

By Vaibhav Gupta