A cell is a basic structural and functional unit of all living things and is also considered a building block of life itself. Within the cell is found many complex structures known as organelles. These organelles range from simple (in Prokaryotes, such as bacteria) to complex, such as the ones found in humans.
Cell Biology, also called cytology is a scientific discipline which studies cells, their processes and their organization. The many structures found in cells are responsible for the life processes that the cells experience. Because cells are such a basic unit of life, the discipline of Cell Biology often overlaps with such other biological disciplines as Genetics, Molecular Biology and Biochemistry.
There are many bodily processes that cells are involved in. One of the most important is the transport of proteins throughout the cell. Proteins are synthesized by organelles known as ribosomes. These ribosomes create proteins from their basic constituents known as amino acids.
Passive and Active Transport are two more processes which take place in the cell and help to move molecules of various sizes across cell membranes. Active transport is a process whereby things in the cell are transported form an area of low concentration to an area of higher concentration. Energy is needed for this type of transport. Passive transport involves the movement of molecules from an area of high concentration and does not involve the use of energy, as molecules can move across the gradient without any help.
Another major process which is studied in Cell Biology is cell division. Cell division involves the production of daughter cells, with a parent cell dividing into at least two daughter cells. In prokaryotes such as bacteria, cell division often takes place by binary fission, a process where the original bacteria (and an occasional eukaryote) replicates its DNA and then divides in half. In most Eukaryotes, the cell’s DNA is replicated and two daughter cells are produced, each with their own DNA and the ability to reproduce themselves.
Another very important function of cells which is a very important part of Cell Biology is cell signaling. Cell signaling is a complex method of communication that cells undertake. Some cells communicate over short or long distances, while some require actual contact to communicate. Proteins known as receptors help the communication between cells of all types.
Cell metabolism is another very important process that the cell undergoes. Metabolism is a series of chemical reactions without which life would not exist. It is necessary for cells to undergo replication, growth and increases their ability to adapt to their environment.
This is just a brief overview of some of the things studied in the scientific field of Cell Biology. For more information check out: http://biology.about.com/od/cellbiology/a/cellbiology.htm