Our body is often referred to as a machine,but have you ever wondered,how this machine works and from where it gets fuel to run . The energy to run this body machine comes from drinks and food that we eat. The process by which body converts food into energy is called METABOLISM. So. Metabolism is a collection of chemical reactions that takes place in the body of CELL. This energy is needed to power everything we do , from moving to thinking to growing. This energy is also required to carry out involuntary processes, like breathing,circulating blood,adjusting hormone levels ,growing and repairing cells.
Metabolism is a constant and continuous process that begins when we are conceived (in mothers womb) and ends when we die. It's a vital process for all life forms. If metabolism stops,living things die.
The process of metabolism is really a balancing act involving two kinds of activities--
ANABOLISM-- it supports the growth of new cells, maintenance of body tissues and storage of energy for future use.
CATABOLISM-- is the process that produces energy required for all the activities of cell.
Both the processes go on continuously side by side.
Several hormones are involved in controlling the rate and direction of metabolism. Apart from many others the two more important hormones are THYROXINE from Thyroid gland and INSULIN from Pancreas .
Metabolism is a complicated chemical process. Most of the time it works smoothly, efficiently and effectively,but sometimes it's not so,then the term metabolic disorder is used. Most metabolic disorders involve either abnormal levels of enzymes or hormones or problems with functioning of those enzymes or hormones.
Sources--several web sites.