Cell biology is a discipline that views the cell as the fundamental unit of life and studies cell structure and function. It seeks to elucidate properties of cells that are universal to all or most cells as well as unique properties that are limited to a small subset of specialized cells.
Cell biology is considered to have begun in the 1830s by Schleiden and Schwann. Schleiden, studying plants, and Schwann, studying animals, were the first to define a cell and state that all living beings were made out of one or more cells. This concept is known as cell theory. The expansion of technology, especially microscopes, allowed scientists to gain higher understanding of cell structure with 3D imaging and electron microscopy.
Cell biology is split into smaller fields that study a particular aspect of cell structure and function. Cell metabolism is the branch of cell biology that studies energy and biochemical mechanisms. Cell communication is a subfield that studies cell signaling and messaging both within one cell and between groups of cells. Cellular genetics looks at the release of genetic information from the nucleus and how proteins control this information release. The study of the phases of cell division and growth is also known as the study of the cell cycle.