Cell Structure (Bio slp Mod 1) Essay Example | Topics and Well Written Essays - 500 words

Cell Structure (Bio slp Mod 1) - Essay Example Additionally, the majority of prokaryotes are unicellular with an exception of a few such as cyanobacteria while eukaryotes are multicellular. These 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. These 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. These 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 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. These 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. This 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