Define Life Processes Class 10

What are life processes ?? 

The maintenance functions of living organism must go on even when they are not doing anything particular. Even when we are just sitting in class, even we are just asleep; this maintenance job has to go on. The processes which together perform this maintenance job our life processes. 

Since these maintenance processes are needed to prevent damage and break-down, energy is needed for them. This energy comes from outside the body of the individual organism. So there must be a process to transfer a source of energy from outside the body of the organism, which we called food, to the inside, a process we commonly called nutrition. If the body size of the organism is to grow, additional raw material will also be needed from outside. Since life on earth depends on carbon-based. molecules, most of these food sources are also carbon-based. Depending on the complexity of these carbon sources different organisms can then use different kinds of nutritional processes.

The outside source of energy could be quite varied, since the environment is not under the control of the individual organism. These source of energy therefore, need to be broken down or build up in the body, and must be finally converted to a uniform source of energy that can be used for various molecular movements needed for maintaining living structures, as well as to the kind of molecules the body needs to grow. For this, a series of chemical reactions in the body are necessary. Oxidising and reducing reactions are some of the most common chemical means to break down molecules. For this, many organisms use oxygen source from outside the body. The process of acquiring oxygen from outside the body, and to use it in the process of breakdown of food sources for cellular needs, is what we called respiration.

In the case of single celled organisms, no specific organs for taking in food. Exchange of gases or removal of waste may be made because the entire surface of the organism is in contact with the environment. But what happens when the body size of the organism increases and the body design becomes more complex? 

In multicellular organisms, all the cells may not be in direct contact with the surrounding environment. The simple diffusion will not meet the requirements of all the cells. 

We have seen previously how, in multicellular organisms, various body parts have specialised in functions they perform. We are familiar with the idea of these specialised issues, and with their Organisation in the body of the organism. It is therefore not surprising that the uptake of food and of oxygen will also be the function of the specialised tissues. However, this poses a problem, since the food and oxygen are Now taken up at one place in the body of the organisms, while all the parts of the body need them this situation create a need for a transportation system for carrying food and oxygen from one place to another in the body. 

When chemical reactions use the carbon source and the oxygen for energy generation, they create by-products that are not only useless for the cells of the body, but could even be harmful. These waste by-products are therefore needed to remove from the body and discarded it outside by the process called excretion. Again if the basic rule for body design in multicellular organisms are followed, a specialised tissue for excretion will be developed which means that the transportation system will need to transport waste away from cells to its excretory tissue.

Let us considered these various processes are essential to maintain life one by one