Life process-Nutrition {biology}

When we do any work, we require energy to do.Energy is needed to maintain a state of order in our body .

We also need materials from outside in order to grow, develop,synthesis protein and other substances needed in the body. These requirements are fulfilled by food that we eat.

How do living things get their food?

The general requirement for energy and materials is common in all living beings but is fulfilled in different ways.Some organisms use simple food materials obtained from inorganic sources in the form of carbon dioxide and water. These organisms are known as autotrophs include green plants and some bacteria. Other organisms utilise complex substances. these complex substances have to be broken down into simpler substances. These organisms are known as heterotrophs  included animals and fungi.

Nutrition in human beings -The alimentary canal is basically a long tube extending from the mouth to the anus.In our body various  regions are specified to perform different functions. 

What happens to the food once it enters in our body?

We shall discuss the process here.

the food that we eat has to pass through the digestive tract.Since the lining of the canal is soft , the food is also wetted to make its passage smooth . when we eat something we like , our mouth waters , this is actually not only water , but a fluid called saliva secreted by the salivary glands . If it is to be absorbed from the alimentary canal, it hasto be broken don into simpler molecules.this is done with the enzymes .

the salva contains an enzyme called salivary  amylase that break don the starch which is complex .the food is mixed with saliva and moved around the mouth while chewing by the mascular tongue .

then the food enters the body and after digestion the body absorbs nutrients from the food .

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