Energy keeps all living organisms alive, as they need a continual supply of energy to function in order to survive. Some of these processes are continuous such as, metabolism, which is the chemical reactions which occur in the body, these occur by using or releasing energy from chemical substances. Another continuous process which use energy is the transporting of molecules in order for them to break down, and to build new ones. The breakdown of large molecules into their simpler forms to release energy is known as catabolism, for example, when glucose is used in a cell to release energy. And the opposite reaction, is called anabolism. This is when energy is used to build complex structures from simple cells, for example, tissue growth and repair. Catabolism and anabolism, are the chemical reactions which are known as metabolism. Whereas other processes such as, muscular contraction and movement only happen at certain times.
The role of energy is essential for muscular activity and movement, but also for the circulation of blood, lymph and tissue around the body, for breathing and taking in oxygen, for making new cells for growth and repair. Energy is also used to transmit nerve impulses to which make the body respond to changes in the environment, and to help build complex molecules such as enzymes, and hormones.
Energy can’t be created or destroyed; although it can be transferred from one form to another. There are two laws of energy: the conservation of energy and the transformation of energy. The conservation of energy is energy which cannot be created of changed, and the transformation of energy is energy which can be changed from one form to another.
There are different forms of energy within the body, these are: mechanical energy, heat energy, sound energy, chemical energy and electrical energy. Examples of these forms of energy are:
• Mechanical Energy