Biological Cell

The Cell is the functional, basic and the smallest unit in the living organism that is capable of integrating the essential life processes. It is often called the building block of life.

All Cells share a number of common properties:

• They store information in genes made of DNA (see nucleic acid).
• They use proteins  as their main structural material.
• They synthesize proteins in the cell's ribosomes using the information encoded in the DNA and mobilized by means of RNA.
• They use adenosine triphosphate as the means of transferring energy for the cell's internal processes.
• They are enclosed by a cell membrane, composed of proteins and a double layer of lipid molecules, that controls the flow of materials into and out of the cell.

Cells can be separated into two major groups:

Prokaryotes cells whose DNA is not segregated within a well-defined nucleus surrounded by a membranous nuclear envelope. The bacteria (kingdom Monera) are prokaryotes. They are smaller in size and simpler in internal structure than eukaryotes and are believed to have evolved much earlier. Prokaryotic cells are usually independent
Eukaryotes cells are those which have a membrane-enveloped nucleus. All organisms other than bacteria consists of one or more eukaryotic cells. Eukaryotic cells are often found in multicellular organisms.

History

Robert Hooke, a British natural philosopher, architect and polymath discovered Cell in 1665. In 1665, Hooke also a physicist, looked at a sliver of cork through a microscope lens and noticed some 'Pores' in it.  These tiny pores that he remarked looked like the walled compartments of a honeycomb. Because of this association, Hooke called them cells, the name they still bear. Robert Hooke believed the cells had served as containers for the "noble juices" or "fibrous threads" of the once-living cork tree. He thought these cells existed only in plants, since he and his scientific contemporaries had observed the structures only in plant material. Hooke did not know their real structure or function. Hooke's description of these cells (which were actually non-living cell walls) was published in a book 'Micrographia'.  However his cell observations gave no indication of the nucleus and other organelles found in most living cells.

Development in the Discovery of Cell

In 1674, Antonie van Leeuwenhoek became the first man to witness a live cell under a microscope. He described the algae Spirogyra  and named the moving organisms animalcules, meaning 'Little Animals'.

In 1838, Matthias Jakob Schleiden, a German scientist used a microscope to study plants and determined that they are made of cells.

In 1839, Theodor Schwann, a German physiologist studied cells and concluded that all animals are made up of cells.

In 1854, Rudolph Virchow, a German doctor discovered that new cells do not form on their own. He decided that new cells form when old cells divide.

Role of the discovery of Cell in the improvement of Human Life

• The observations of Hooke, Leeuwenhoek, Schleiden, Schwann, Virchow, and others led to the development of the cell theory.

• It made it clear to the scientific community that all organisms are made up of one or more cells.

• The discovery led to various research and studies which helped in improving the health of the worldwide populace.