The cell is the most basic form of life essentially. Anything that is living fundamentally is composed of cells. We study the cell because it is the simplest unit of all living organisms and to begin understanding life, we must realize the cell’s structure, whether it is about the different types of cells or how the cell functions. Biology is the study of life and for the human species; the cell is the most basic principle of life, which is why it is so important to understand the complexities of cells.
There are two basic categories of that all cells fall under. They are prokaryotic cells and eukaryotic cells. Prokaryotic cells are single-celled organisms that include bacteria and archaea. Eukaryotic cells are more complex cells that include protists, plants, fungi, and animals. The major difference of prokaryotic and eukaryotic cells is that prokaryotic cells do not have a nucleus and eukaryotic cells do. Prokaryotic cells are also a lot smaller than eukaryotic cells, usually about 1/10 of the size of eukaryotic cells. Prokaryotic cells are the oldest primitive form of life through findings of fossils by scientists. Both types of cells reproduce, but each have a different process of reproduction. Prokaryotic cells reproduce through a process called binary fission and eukaryotic cells reproduce through a process called mitosis. DNA structures of eukaryotic cells are far more structured than that of prokaryotic cells. The DNA of eukaryotic cells is organized into chromosomes and the DNA of prokaryotic cells is a single loop. Both prokaryotic and eukaryotic cells gain the energy it needs to develop and maintain functionality by a process of cellular respiration. Basically, cellular respiration is broken down in three general phases: electron transport, glycolysis, and the citric acid cycle. In eukaryotic cells, cellular respiration usually reacts within the mitochondria; and in prokaryotic cells,
References: The Cell-Cell Structure, Eukaryotic Cells and Prokaryotic Cells, By Regina Bailey, About.com, http://biology.about.com/od/cellanatomy/a/eukaryprokarycells.htm, Accessed on August 6, 2011. Campbell Essential Biology with Physiology Vital Source eBook for South University, 3rd Edition, Eric J. Simon, New England College, Jane B. Reece, Berkeley, California, Jean L. Dickey, Clemson University, Chapter 4 – Tour of the cell, http://digitalbookshelf.southuniversity.edu/#/books/0558586805/pages/28225209, Accessed on August 6, 2011. Why are cells important? Topic 1.1, http://www.mcgrawhill.ca/web_resources/sch/SL10_sample_unit1_topic1_1.pdf, Accessed on August 6, 2011.