Why We Study the Cell and It's Components

Biology studies the basics of life in which we examine living organisms to help us

understand how everything works. In order to understand life we first have to look at its

components. The basic of the living unit is the cell. All living things or organisms are

composed of these cells. Both animals and plant are comprised of cells. And let's not

forget the invisible world of bacteria. For without bacteria we could not live. It is more

helpful than harmful.

There are two basic cellular constructions, the prokaryotes and eukaryotes. Rudolf

Virchow (1850) stated, "Cells come from other cells." Living organisms are formed when

one or more cells carry out living activities. This includes reproduction by the process of

cell division. Organisms may be composed of one cell or many. Prokaryotic cells do not

have a nucleus whereas the eukaryotic cell contains a membrane-enclosed nucleus. This

nucleus is the command center of the cell. It tells all the little organs what to do.

Prokaryotes being the older of the two cells first appeared on earth over 3.5 billion

years ago, as for the eukaryotes cells, which appeared 2.1 billion years ago. Prokaryotic

cells tend to be smaller. They can be up to one tenth smaller than the eukaryotic cell and

the cellular structure is much simpler.

Even though prokaryotes seem more primitive than eukaryotes, their simple, small,

and single-celled organisms can reproduce faster and evolve more rapidly.

The eukaryotic cell has more cellular functions than prokaryotic cell. They contain

membrane-bound organelles, which carry out the life processes of the cell. Cellular

organelles are little organ structures within cells. They each have specific jobs to do.

The three major components of a cell containing organelles are the Plasma Membrane,

the Nucleus and the Cytoplasm. The Plasma Membrane protects the cell. It is an outer

layer of protective protein, separating the interior of the cell from