What are Life Processes?
Movements over very small scale are invisible to us. Molecular activity that takes place in our body cannot be seen by naked eye. But these movements are necessary for creation of new cells and repairing and maintenance of the existing or damaged cells in our body. The maintenance of any living tissue requires energy which is obtained by molecular movements in the bodies of various organisms which make life possible. These 4 processes are interconnected and essential for a life form to exist.
The 4 processes that are essential for life to exist, namely:
1. Nutrition
2. Respiration
3. Transportation
4. Excretion
1. Nutrition (Intake of Carbon based compounds - Why?)
A process to transfer a source of energy from outside the body of the organism, which we call food, to the inside, a process we commonly call nutrition.
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.
2. Respiration (Exchange of Gases - Why?)
The food must be finally converted to a uniform source of energy that can be used for the various molecular movements needed for maintaining living structures, as well as to the kind of molecules the body needs to grow. Oxidizing-reducing (Redox) reactions are some of the most common chemical means to break-down molecules. The process of acquiring oxygen from outside the body, and to use it in the process of break-down of food sources for cellular needs, is what we call respiration.
3. Transportation (Transportation of Energy to various parts of the body)
In multi-cellular organisms, all the cells may not be in direct contact with the surrounding environment. Thus, simple diffusion will not meet the requirements of all the cells. This poses a problem, since the food and oxygen are now taken up at one place in the body of the organisms, while all parts of the body need them. This situation creates a need for a transportation system for carrying food and oxygen from one place to another in the body.
4. Excretion (Removal of waste products from 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 be removed from the body and discarded outside by a process called excretion.
Nutrition
We need energy to maintain a st