September 20th, 2012

PROKARYOTIC VS. EUKARYOTIC CELLS:

1. • 1
     Compare by size. Prokaryotic cells are significantly smaller than eukaryotic. In fact, eukaryotic cells are typically about ten times larger than prokaryotic cells. The size of cells is usually measured in micrometers, with the average prokaryotic cell being around one micrometer wide.
   • 2
     Compare by organization: Eukaryotic cells’ organization is quite complex, especially in comparison to prokaryotic cells. They contain a nucleus as well as several organelles that each perform a particular function. Some of these include the mitochondrion (processes energy from food), smooth endoplasmic reticulum (involved in creating carbohydrates and lipids), rough endoplasmic reticulum (involved in the production of proteins), Golgi complex (the distribution center for molecules), and the lysosome (the recycling center for old organelles). In stark contrast, prokaryotic cells do not have these organelles performing functions within them. They do not even have a nucleus.
   • 3
     Compare by method of division: Cell division in prokaryotic cells is done through a process known as binary fission. In binary fission the original or parent cell splits to form two cells, with the second or daughter cell identical to the parent. As with other characteristics, the eukaryotic cell uses a more complex method of division called mitosis. According to Cornell University’s Department of Plant Pathology, mitosis is defined as, “a sequence of cellular events that culminates in the division of a eukaryotic nucleus into two genetically similar or identical nuclei whose ploidy is the same as that of the parent nucleus.”
   • 4
     Compare by presence of a cell wall: A cell wall can be thought of as an external layer or structure that protects the interior of the cell. Bacteria, which are made of prokaryotic cells, almost always have a cell wall. Plant cells, which are eukaryotic, have cell walls as well, but the eukaryotic animal cells do not.
   • 5
     Compare by kingdom: Organisms made up of eukaryotic cells are members of the protista, fungi, plant, and animal kingdoms. In contrast, the only two remaining kingdoms made up of only prokaryotic cells are archaea and bacteria.