The cell is the fundamental building block of life in all living organisms. Cells possess numerous intricate and complex structures which serve specific functions. A high level of functional co-ordination between these structures is essential for maintaining the health and well-being of any organism. The focus of this article is to provide engineers, with little or no knowledge of biology, a general overview of the major structural components constituting a cell, a brief description of the basic functions of cells, examine how cells can be compared with a living structure and machine and finally how a break down of some of the functions and/or structural components underlie disease initiation and progression in human body. An understanding of this can lead to a better insight into the structure-property-function relationship of living cells in health and in disease.