Cell Structures: Prokaryotic & Eukaryotic Cells

Bacterial cells are Prokaryotic cells. These cells have several internal structures and surface structures. The cell walls are of two types, gram positive and gram negative. Out of all the structures, the two selected structures are the cell- wall and endospores. The cell- wall of bacterial cells is found in three distinct shapes such as spherical, spiral and rod shaped. The cell wall of the bacterial cells is composed of the proteins and polysaccharides. This is collectively called peptidoglycan. The cell- wall helps the bacterial cell to survive at a greater degree, as an independent unicellular organism. This provides protection to the cell from the turgor pressure, which is raised due to an increased level of protein concentration in the cells. The cell- wall is very important because it determines the shape of the particular cell (Bacterial Cell Structure, 2009).

The second structure of the prokaryotic bacterial cell is endospore. These are the internal structure of the bacterial cells. This is a tough and inactive structure of the bacterial cell, which does not take part in reproduction. In well- developed endospores, multiple numbers of layers are found in the resistant coat. These layers consist of the spore coat and the cortex. The endospores have a thin covering over them called exosporium. The endospores are composed of metabolic and protective proteins, calcium dipocolinate. The spore coat is made up of keratin like protein. Exosporim is made up of lipids and proteins. In the composition of the endospores, the RNA molecules and enzymes also take part. The endospores are the cell structures, which help the cells to survive in the adverse environmental conditions and chemical effects. It reduces the stress on the cells of the higher degree of temperature (Kaiser, 2007). These structures are very important, as they have a resistance capacity to the radiations, antibiotics, disinfectants, etc.

The other category of the cells is Eukaryotic cells. These cells are classified into animal cells, plant cells, algae and fungi. Animal cells have several cell organelles. Out of these organelles, the two important organelles essential for the survival of the cells are Mitochondria and Lysosomes. Mitochondrion is a cell organelle bounded by a membrane. Their diameter has a range of 0.5 to 10 micrometers. Mitochondrion is composed of an outer membrane and inner membrane, a fluid called matrix and figure like structures cristae. The size of the mitochondria is just like the size of bacteria and the shape of the mitochondria varies according to different cell types. The function of the mitochondria is to store energy for the functioning of the cells. The mitochondrion is therefore known as Power plant of the cell. This is very important for the survival of the cells. These are essential for the survival of the cell because all the processes of the cell such as movement, cell division, production of secretory thins etc. only takes place with the help of the energy stored in mitochondrion (Animal Cells, 2006).

The other important cell organelles are the Lysosomes. These organells are composed of several digestive enzymes. The lysosomes contain hydrolytic enzymes. The lysomsomes are bag like structures, which have a range of size between 0.1 and 1.2 micrometer. They are composed of golgi complex. These are also known as Suicide bags. Their functions in the cells are very important, which is known as Autolysis. They engulf and digest the excess cell organelles, particles of food and viruses found in cells. They play a very important role in the survival of the cells. They digest the foreign bacteria and also help in the repairing of the plasma membrane by filling the wounds, found in the membrane. Thus lysosomes are very important cell organelles, which functions for the protection of the cells (Animal Cells, 2006).

ReferencesAnimal Cells, (2006). Retrieved June 17, 2009, from http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/A/AnimalCells.htmlBacterial Cell Structure, (2009). Retrieved June 17, 2009, from http://www.cellsalive.com/cells/bactcell.htmKaiser, G, E. (2007). The Prokaryotic Cell: Bacteria. Retrieved June 17, 2009, from http://student.ccbcmd.edu/courses/bio141/lecguide/unit1/prostruct/spore.html

References: nimal Cells, (2006). Retrieved June 17, 2009, from http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/A/AnimalCells.htmlBacterial Cell Structure, (2009). Retrieved June 17, 2009, from http://www.cellsalive.com/cells/bactcell.htmKaiser, G, E. (2007). The Prokaryotic Cell: Bacteria. Retrieved June 17, 2009, from http://student.ccbcmd.edu/courses/bio141/lecguide/unit1/prostruct/spore.html