Eukaryotic Cells

Introduction: Prokaryotic cells are cells that do not have membrane bound organelles, such as ribosomes and include organisms such as bacteria. In contrast, eukaryotic cells contains organelles and are often more complex organisms (Karp, 2010). These cells have some similar features such as the plasma membrane and the use of ribosomes to make proteins. However, there are also significant differences between prokaryotic and eukaryotic organisms.
Whilst the prokaryotic/ eukaryotic classification system is useful, it has to be acknowledged that it is flawed. Another system is the Phylogenetic tree of life, also known as the three domain system (Woese, 1985). This uses ribosomal sequencing to place organisms in to three groups; Archaea, Bacteria and Eukaryotes. This essay will explore which system is more useful in categorising …show more content…
For example, both types of cell have a plasma membrane which surrounds and protects the cell, acting as a semi permeable barrier. (Karp, 2010). The eukaryotic and bacterial plasma membrane has a similar structure, whereas than the plasma membrane in archaea has a different structure. The prokaryotic plasma membrane is made of lipids, consisting of straight chained hydrocarbons, joined by ester bonds. In comparison, the archaeal plasma membrane is made of lipids consisting of isoprenoid hydrocarbon chains linked with ether bonds (Oger and Cario, 2013). The plasma membrane suggests that the three domain groups originated from the same organism because it is common to all groups and plays the same role. However, the composition of the lipids in the plasma membrane is different in each group, showing they have significantly evolved since LUCA. The features of the plasma membrane shows that the 2 domain naming system has limited use because archaea have significant differences from bacteria, which the system does not