What are nutrition and its types?

Nutrition is the process of consuming foods to carry out the vital functions of the body for survival. Nutrients are the substances that provide nutrition to the living organisms for performing proper functions and growth.

There are seven major nutrients that are required by the body in order to maintain its proper functionality.

They are carbohydrates, proteins, fats, water, vitamins, minerals, and fibres.

There are two types of nutrition: Autotrophic nutrition and Heterotrophic nutrition.

(1) In autotrophic nutrition, the organisms prepare their own food through the process of photosynthesis in the presence of sunlight, carbon dioxide, water, minerals, and pigment such as chlorophyll, phycocyanin, phycoerythrin etc. Examples: Plants, blue-green algae, few photosynthetic bacteria, etc.

(2) In heterotrophic nutrition, the organisms depend on autotrophic organisms for their nutrition.

Examples: Human beings, animals, birds, reptiles, etc.

Heterotrophs are further divided into three categories based on their mode of nutrition.

(i) Holozoic nutrition: It is the mode of nutrition that involves the ingestion, digestion, absorption, and assimilation of solid and liquid food material to obtain nutrients.

(ii) Saprotrophic nutrition: In saprotrophic nutrition, the organisms feed on dead or decaying organic material by secreting enzymes on it and absorbing nutrients.

(iii) Parasitic nutrition: It is the mode of nutrition where an organism derives its nutrition by harming or damaging the other organism.