NUTRITION IN GENERAL SUMMARIZED

Introduction

We have seen how plants make food from basic raw materials. Animals cannot do this. They rely on plants as the source of all their nutrients and energy. In this unit, you will learn about what happens to food after you have eaten it. You will find out about the structure of your digestive system, and how food is digested and absorbed into your body. *NOTE IT: Organic- a substance containing carbon made by a living organism. Inorganic- a substance that has not been made by a living organism and often does not contain carbon*

Nutrition
Nutrition is the process whereby organisms obtain organic and inorganic substances for their energy and their raw materials for growth and tissue repair. The way in which green plants and animals obtain their food is very different:
• Green plants turn simple inorganic chemicals into complex ones.
• Animals take in complex organic substances from plants.

Ways Of Nutrition
Plant and Animals obtain their food in different ways. The way in which plants obtain their food is called autotrophic nutrition, and the way in which animals obtain their nutrients is called heterotrophic nutrition. Let us look at the main differences between the two ways in which plants and animals obtain their energy.

The differences between Autotrophic and Heterotrophic nutrition
Autotrophic Nutrition

This type of nutrition involves obtaining food by taking in simple, inorganic substances, such as water and minerals from the soil, and carbon dioxide from the air as raw materials, and combining them to make complex organic materials, such as carbohydrates, proteins and fats. Plants are autotrophic organisms. They make their own food during the process of photosynthesis by obtaining inorganic materials and building them into organic materials, using sunlight as a form of energy. 'Photo' means "light' and 'synthesis' means 'to combine', hence the term photosynthesis. The term autotrophic literally means self-feeding. 'Auto' means 'self' and 'trophic' means 'feeding'.

Heterotrophic Nutrition

This is a way of nutrition that involves obtaining complex organic materials and using them as a source of energy and for growth. Animals cannot make their own food. They feed on organic materials, which are made by plants. The way in which animals feed is called heterotrophic nutrition. 'Hetero' means 'others' and 'trophic' means feeding. Some animals feed on other animals, but plants originally made all the organic materials that they take in.

Heterotrophic Nutrition Is Divided In Three Groups:

Holozoic Nutrition

This type of nutrition involves the taking in of food through the mouth (opening). Once taken in
the food particles are broken down into simpler forms. Finally, the essential nutrients are absorbed by the body and the unwanted and undigested portions are eliminated, for example, Amoeba.

Saprophytic Nutrition
This type of nutrition involves processing or decomposing the rotten foliage and dead or decaying organic matter of organisms. Examples are fungu like mushrooms yeasts and moulds.

Parasitic Nutrition

The word parasitic is derived from the word 'parasite'. 'Para' is a Greek term for feeding and 'site denotes grains. Parasitic nutrition is a mode of heterotrophic nutrition where an organism (known as a parasite) lives on the body surface or inside the body of another type of organism (known as a host).
For instance, a hookworm lives in the intestine of humans and feeds on it without going through the process of ingestion or egestion. This nutrition is viable for those organisms that do not possess properly developed organs and depend on their host's body for deriving nourishment. Examples are cuscuta, tapeworms, leeches, plasmodium, and so on.

Try Out This Activity
This activity should take about 5 minutes. Complete the following sentences.
The type of nutrition carried out by the green plants is called 1._________. It uses energy from the 2.__________ to build complex 3._________ simple 4.________. Heterotrophic nutrition is carried out by 5.________. It involves the taking in of 6.__________ made by the plant. These materials are used for growth and 7.__________.

Stay Tuned As Next Post We'll Look At Plant Nutrition. Posted by Mrs Smith Merlin.