Cell Structure (Bio slp Mod 1) - Essay Example

Cell Structure -Deep-water Horizon Oil Spill Cell Structure -Deep-water Horizon Oil Spill Prokaryotic and Eukaryotic cellThe cell is the building unit in living organisms both simple and complex. Consequently living things can be broadly classified into prokaryotes or eukaryotes depending on their cell structure. These two groups differ by their subcellular structure where eukaryotes have membrane bound organelles, while prokaryotes lack these organelles. Eukaryotic cell, therefore, contain complex structures formed by internal membranes and cytoskeleton whereas, prokaryotic cells are simple with less complex structured organelles.

Theorists postulate that prokaryotes were the only form of life for millions of years before eukaryotes come into being through evolution. Additionally, the majority of prokaryotes are unicellular with an exception of a few such as cyanobacteria while eukaryotes are multicellular.ArchaeaThese are single-celled prokaryotic organisms that differ from bacteria and eukaryota in many ways. Their size and shape resemble that of bacteria but contain genes and metabolic processes similar to those in eukaryotes.

Unlike bacteria, some archaea have irregular shapes.Nitrifying bacteriaThese are prokaryotic organisms that derive their energy from inorganic sources. They are subdivided into two major groups; ammonium oxidizing bacteria (AOB) that oxidize ammonia to nitrite, and nitrate oxidizing bacteria (NOB), which oxidize nitrite to nitrate. Examples of the AOB group are the Nitrosomonas Sp while Nitrobacter Sp belong to the NOB group.Ammonium-oxidizing bacteriaThese are chemolithotrophs bacteria that utilize ammonium as a source of energy.

They oxidize ammonia to nitrite. Examples include the Nitrosomonas, Nitrosococcus, Nitrosospira, and Nitrosolobus species.Gram-negative VS Gram-positive bacteriaGram negative bacteria are bacteria that have a thin peptidoglycan (polymer) matrix, which comprises the cell membrane of the organism. Consequently these bacteria do not retain the crystal violet dye used in gram staining technique. On the other hand, gram positive bacteria contain a thick layer of this polymer matrix, thus retain the primary stain in gram staining giving them purple appearance.

HydrocarbonThese are organic compounds consisting of carbon and hydrogen elements. These compounds are abundant in nature and occur mostly in the form of crude oil. Hydrocarbons, therefore, are the main source of energy readily available as a combustible fuel.BioassayThis is a scientific assay that employs the use of live organisms to determine the biological activity of a test substance. These tests are useful in investigating the effects (toxicity) of an element accidently introduced in an ecosystem.

For instance, the effect crude oil spills on the surface and deep-water marine life. Bioassays can be qualitative or quantitative.Microtox bioassayMicrotox is a commercial bioassay kit that monitors growth activity of Vibrio (Allivibrio) Fischeri. The growth of the microorganism is monitored and quantified through bioluminescence.Crude oilThis is a naturally occurring hydrocarbon liquid found beneath sedimentary rocks. This organic compound can be refined into various petroleum products, which form the various types of biofuels.

BiodegradationBiodegradation is the breakdown of organic or inorganic matter into primary elements by living organisms. This process is mediated by enzymatic processes in the living cells and bacteria form the majority of organisms used in this process.Sensitivity Bioassay studyThe study by Urakawa (2012) investigated the toxicity of oil spills on nitrifying microorganisms. In this study, both nitrifying bacteria and archaea toxicity were reported at 0.1-10ppm concentration of the contaminant (Urakawa, et al 2012).

However, archaea were reported to have a higher sensitivity to toxicity than bacteria. The toxicity sensitivity to crude oil also varies with species among nitrifying bacteria group, with N. maritimus showing a higher sensitivity than the rest (Urakawa, et al 2012). A significant difference in sensitivity is also noted between betaproteobacterial, which showed a higher sensitivity than gammaproteobacterial ammonia oxidizers (Urakawa, et al 2012). To determine the impact of chronic toxicity on microorganisms, Urakawa (2012) challenged the growth of heterotrophs with increasing doses of toxicity from zero to 10 ppm oil concentration (Urakawa, et al 2012).

Significantly this group had a low sensitivity compared to that of nitrifying bacteria.ReferencesUrakawa, H. et al. (2012). “A sensitive crude oil bioassay indicates that oil spills potentially induce a Change of major nitrifying prokaryotes from the Archaea to the Bacteria.” Environmental Pollution 164: 42-45