Earth is surrounded by organisms which have independent roles to maintain various life processes. Microorganisms can be defined as living things that are invisible to our naked eyes and found abundantly in our environments. On the basis of ribosomal RNA (ribonucleic acid) sequencing, microorganisms are divided into three phylogenetically distinct domains, which has included the Archaea, the Bacteria and the Eukarya (Madigan, Martinko, Stahl, & Clark, 2012) (refer to Figure 1 in Appendix 1).
Archaea is the first domain of microorganisms. Archaeas are unicellular prokaryotes which vary from bacteria and eukaryotes (Pack, 2007). Pack (2007) stated that the cell walls of Archaeas consist of polysaccharides while the plasma membranes are made up of phospholipids. According to Cohen (2011), archaeal cell walls do not have peptidoglycan, cellulose or chitin. There are four main differences between archaeal membrane and other cells (Cohen, 2011). For instance, the hydrophobic chains of phospholipids are highly branched and ether-linked to glycerol (Pack, 2007). Archaeas have irregular shapes such as spheres, rods, or spirals (Levy, 2011) and some are triangular or square-shaped (Soloman, Berg & Martin, 2011). Besides that, Archaeas reproduce asexually through binary fission but not mitosis because the nucleus is absent (Hogan, 2011). Bej, Aislabie, and Atlas (2010) stated that the two main phyla of Archaeas are Crenarchaeota and Euryarchaeota.
According to Kratz (2005), most of the Crenarchaeota are hyperthermophiles that grow at temperature above 80oC. Kratz (2005) also mentioned that hyperthermophiles prefer to live in hot habitat with high sulfur contents such as volcanoes. Sulfolobus was the first types of hyperthermoph...
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...Ed.). (2011). Bacteria and viruses. New York, NY: Britannica Educational Publishing.
Salton, M. R. J. (1953). Studies of the bacterial cell wall: IV. The composition of the cell walls of some gram-positive and gram-negative bacteria. Biochimica et Biophysica Acta, 10, 512-523.
Solomon, E. P., Berg, L. R., & Martin, D. W. (2011). Biology. Belmont, CA: Brooks/Cole, Cengage Learning.
Srivastava, S. (2012). Understanding bacteria. Dordrecht, Netherlands: Kluwer Academic Publishers.
Vellai, T., & Vida, G. (1999). The origin of eukaryotes: The difference between prokaryotic and eukaryotic cells. Proceedings of the Royal Society of London. Series B: Biological Sciences, 266(1428), 1571-1577.
Whitman, W. B., Coleman, D. C., & Wiebe, W. J. (1998). Prokaryotes: The unseen majority. Proceedings of the National Academy of Sciences of the United States of America, 95(12), 78-83.
Madigan, Michael T. et al. Brock biology of Microorganisms. 13th ed. California: Benjamin Cummings, 2012. Print.
As for organisms in the world from humans to the smallest microbe, they directly reflect upon biodiversity, in respect to the appearance, size and expression. The reason behind this is caused by the genetic material found in each and every cell that composes each organism. Given that there are two types of cell organizations found in life, comparison of both ‘eukaryote’ and ‘prokaryote’ genomes will provide a better understanding for such diversity. ‘karyote’ refers to the nucleus, and also ‘pro’ means ‘absence’ and ‘eu’ means ‘presence’. Therefore the words prokaryote and eukaryote reflect upon the individual cell organization. In contrast, the both organizations show discrepancies as well as similarities which ultimately make them unique to one and other.
Lodish H, Berk A, Zipursky SL, et al. Molecular Cell Biology. 4th edition. New York: W. H.
Eukaryotic cells, whether from animals, plants, protists, or fungi, are the most structurally advanced of the major cell types. Eukaryote are single-celled or multicellular organism whose cells contain nucleus and any other structures (organelles) enclosed within the membrane that perform specific functions. The surface of the cell is covered with a thin film or plasma membrane, which is the boundary that separates the living cell from its nonliving surroundings. Plasma membranes are composed mostly of proteins and lipids (Simon, 02/2012, p. 59-60).
C) The photo of prokaryotes on slide 6 of module 14 shows that it ...
Talaro , K., & Chess, B. (2012). Foundations in microbiology. (8th ed., pp. 563-564). New York, NY:
Rastogi, G. and Sani, R.K. (2011) 'Chapter 2 :Molecular Techniques to Assess Microbial Community Structure, Function, and Dynamics in the Environment', in Ahmad, I., Ahmad, F. and Pichtel, J. (ed.)Microbes and Microbial Technology. California, USA: Springer Science, pp. 29-57.
Bacillus Subtilis is an extremely common bacterium that is gram positive. It is found in soil and to tolerate extreme environmental factors, it forms a tough protective endospore. This bacterium is also rod shaped. (Probiotic,
3 Leicht B. G., McAllister B.F. 2014. Foundations of Biology 1411, 2nd edition. Southlake, TX: Fountainhead Press. Pp 137, 163-168, 177-180,
“David M. Lodge // Department of Biological Sciences // University of Notre Dame.” University of Notre Dame. 2009. Web.1 Mar. 2010.
The history of Ab starts when “the Dutch microbiologist, Beijerinck, first isolated the bacteria from soil using minimal media enriched with calcium acetate, in 1911” (Aoife et al. 244). From there different characteristic of Ab were noted, such as, “Ab is often found in pairs, does not use oxygen, does not produce nitrites, does not move, and it can be isolated on a MacConkey agar, which is a specific media of petri dish” (Rosenbaum et al. 10). Using a staining method, it is determined that Ab is a gram-negative bacterium, because it does take on the stain. Although, Ab can be difficult to de-stain, making it harder to distinguish between gram-negative or positive (Aoife et al 244). “It also has the ability to survive longer in any environment, even on dry surfaces, because it is resistance to desiccation, or being completely deprived
Endosymbiosis is the theory that eukaryotic cells were formed when a prokaryotic cell ingested some aerobic bacteria. The first step of the evolution of a eukaryotic cell is the infolding of the cellular membrane. This process takes place when the plasma membrane folds inwards and develops an envelope around a smaller prokaryotic cell. Once the smaller cell is engulfed, it becomes dependent upon its host cell. It relies on the host cell for organic molecules and inorganic compounds. However, the host cell also benefits because it has an increased output of ATP for cellular activities and becomes more productive. This ATP comes from the mitochondrion (the aerobe) that is engulfed.
A Prokaryote is a single cell organisms that does not have a nucleus, which is divided into two major groups: archaeabacteria and bacteria. Prokaryotes are usually found in three common structures, such as bacillus is rod shaped, crocus is spherical-shaped, and spirillum is long shape. Although there are prokaryotes that are responsible for diseases there are also good types of bacteria that we need. Prokaryotes provide essential services to biological systems for instance food and agriculture.
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.
There were three bacteria that were studied during this experiment. Staphylococcus is a type of bacteria that is often found on the body of human beings and animals. It is found on the skin and hair as well as in the noses and throats. Staphylococcus can cause food poisoning when it is exposed to food and contaminated because the food is not properly refrigerated. (Food Safety) These bacteria are Gram-positive with a spherical shape that often group into clusters, much like grapes. (Bacteriology) The only way to kill these bacteria is by cooking and pasteurization. Bacillus cereus is a type of bacteria that produces toxins that can cause two types of illnesses. One type causes diarrhea and the other causes nausea and vomiting. These bacteria are found in foods and multiple rapidly at room temperature. (Food Safety) Bacillus cereus is also Gram-positive and is rod-shaped and very large. It can spread easily to many types of foods such as plants, eggs, meats, and dairy products. (MicrobeWiki) Escherichia coli is bacteria found in the gastrointestinal tract and are able to produce a toxin that can produce serious infections. This bacterium can be acquired by consuming contaminated food or water. (European Centre) E. coli is often used to help your body break down and digest certain foods. It becomes dangerous when the bacteria go from the intestines into the blood. (Kids Health) Escherichia coli, unlike any other bacteria that was studied, is Gram-negative. It is also rod shaped and is about average size. (Mansfield)