Friday, September 5, 2014

All Living organisms need Food


They Need it as a source of raw material to build new cells and tissues as they grow. They also need food as a source of energy . Food is a kind of fuel of living organisms like automobiles require petrol or diesel. In living organisms food drives essential living processes and brings about chemical changes. It provides materials to maintain various processes of life such as reproduction, respiration etc.
Living organisms can be divided in to two groups on the basis of their mode of nutrition.
1. Autotropghic organisms
2. Heltrotrophic organisms

1. Autotrophic organisms: Organisms , which can symthesize their own organic compounds (Food) from inorganic raw material taken from inorganic to pass through the cell-membrane. Most of the autotrophic are photosynthetic e.g Plants, algae some Bactria etc.

2. Heterotrophic Organisms: Organisms, Which are unable to synthesize their own organic compounds (food) from simple inorganic nutrients. They obtain synthesize food from their environment. many of the organic molecules found in nature are too large to be absorbed unaltered through cell membranes and they must first be digested i.e broken down into smaller , more easily absorb ale molecular units. 
The food of heterotrophic organisms consists of following components.
1. Carbohydrates 
2. Proteins 
3. Fats 
4. Vitamins 
5. Minerals 
6. Water

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