LUCA Argumentative Essay

All life on earth is said to have evolved from a common ancestor. This common ancestor is called LUCA. LUCA stands for Last Universal Common Ancestor. From LUCA life evolved into the three domains that we know today. This is the 3 domain system proposed by Carl Woese. This system suggests that there are three forms of life. The Prokaryotes, Eukaryotes and the Archaea. Some research has been conducted that suggests the Eukaryotes formed from a cell fusion between an Archaea and a Prokaryote. This theory explains how the Eukaryotes become such a specialised life form. They were able to incorporate features from both Archaea and Prokaryotes. However, there are some missing pieces of information in the prokaryote to Eukaryote transition, has meant that scientists have been unable to get a detailed idea of the forces that have driven eukaryogenesis. A new line of Archaeal lineage called the TACK super phylum has been discovered. Lokiarchaeota is part of the TACK super phylum. This holds vital information about how Eukaryotes first formed on Earth. [Spang, A et al. (2015)]

Due to the theory of the cell fusion of

Through techniques as microscopy it can be seen that both Prokaryotes and Eukaryotes have membrane lipids which are unbranched hydrocarbons. A hydrocarbon is a molecule that contains solely hydrogen and carbons. Eukaryotes and Prokaryotes have 3 main types of membrane lipids. [Berg, JM et al., 2002] The three types are Phospholipids, Glycolipids and Cholesterol. A phospholipid molecule is made up of 4 separate groups. 2 Fatty Acids group that are attached to a Glycerol molecule, which has a phosphate group attached and an Alcohol group joined to the phosphate. Phospholipids form a phospholipid bilayer. Glycerol molecules are sugar containing molecules. However, Cholesterol can only be found in Eukaryotic cells and not in Prokaryotic cells. Cholesterol is a steroid as it has 4 hydrocarbon