The purpose of the lab was to be able to see the effect of Triton X – 100 on the viability of Tetrahymena thermophile, a unicellular protozoan. This organism is motile and it uses cilia, which are thick protuberances that project out from the body and beat in rhythmic waves to move around. An advantage to using T. thermophila as the test organism is that the cell can be tested directly, it is also fast, cheap and the toxicants can be added to test viability (Rowan & Goldberg, 1985). This experiment acts as a bioassay, a scientific experiment that measures the effect of toxicants or substances on living organisms (Ward & Codd, 1999). Triton X – 100 is a surfactant that is non-ionic, meaning that it contains a hydrophobic head that is uncharged and a hydrophilic chain (Dayeh et al, 2005). This toxicant is commonly used in detergents, in experiments, laboratory work, cleaning products, food products and pharmaceuticals (Ward & Codd, 1999). Triton X- 100 interrupts the hydrogen bonding of the lipids in the lipid bilayer and ultimately destroys the integrity of the membrane. This lyses the cell and …show more content…
The experiment tested the T. thermophila directly, and thus making this experiment very ideal for toxicologist. The toxicant Triton X – 100 was also a very ideal toxicant to test because it is one of the most common types of toxicants used in laboratory. The protozoa reproduced rapidly and produces numerous offspring (Cassidy-Hanley, 2012). It is also inexpensive to store and maintain which makes it ideal for repetitive testing (Cassidy-Hanley, 2012). Although this experiment offers many pros to testing toxicology, there are also cons associated to this experiment. The T. thermophila, when isolated for testing in most cases, does not provide a clear representation in terms of how the protozoa interacts within its environment and surroundings. Therefore, it compromises any survival
The unknown bacterium that was handed out by the professor labeled “E19” was an irregular and raised shaped bacteria with a smooth texture and it had a white creamy color. The slant growth pattern was filiform and there was a turbid growth in the broth. After all the tests were complete and the results were compared the unknown bacterium was defined as Shigella sonnei. The results that narrowed it down the most were the gram stain, the lactose fermentation test, the citrate utilization test and the indole test. The results for each of the tests performed are listed in Table 1.1 below.
The goal of this two week lab was to examine the stereochemistry of the oxidation-reduction interconversion of 4-tert-butylcyclohexanol and 4-tert-butylcyclohexanone. The purpose of first week was to explore the oxidation of an alcohol to a ketone and see how the reduction of the ketone will affect the stereoselectivity. The purpose of first week is to oxidize the alcohol, 4-tert-butylcyclohexanol, to ketone just so that it can be reduced back into the alcohol to see how OH will react. The purpose of second week was to reduce 4-tert-butylcyclohexanol from first week and determine the effect of the product's diastereoselectivity by performing reduction procedures using sodium borohydride The chemicals for this lab are sodium hypochlorite, 4-tert-butylcyclohexanone
Planarians are free-living, carnivorous flatworms found in the Phylum Platyhelminthes, Class Turbellaria. Although the Phylum Platyhelminthes is known for having the animals with the most parasitic species, the class Turbellaria which consist of the Planaria, are a non-parasitic species. Platyhelminthes which translates to "flat worm" are triploblastic animals. This means that they have three tissue layers, the endoderm, mesoderm, and ectoderm. Planaria also are monoecious organisms, meaning that they have both female and male sex organs in one organism. Another characteristic of the Planaria is that they do not have a true body cavity, meaning that they are acoelomate organisms.
In this lab 4-tert-butylcyclohexanone is reduced by sodium borohydride (NaBH4) to produce the cis and trans isomers of 4-tert-butylcyclohexanol. Since the starting material is a ketone, NaBH4 is strong enough to perform a reduction and lithium aluminum hydride is not needed. NaBH4 can attack the carbonyl group at an equatorial (cis) or axial (trans) position, making this reaction stereoselective. After the ketone is reduced by the metal-hydride, hydrochloric acid adds a proton to the negatively charged oxygen to make a hydroxyl group. The trans isomer is more abundant than the cis based on the results found in the experiment and the fact that the trans isomer is more stable; due to having the largest functional groups in equatorial positions.
The Effect of pH on the Activity of Catalase Planning Experimental Work Secondary Resources Catalase is a type of enzyme found in different types of foods such as potatoes, apples and livers. It speeds up the disintegration of hydrogen peroxide into water because of the molecule of hydrogen peroxide (H2O2) but it remains unchanged at the end of the reaction.
Disease and parasitism play a pervasive role in all life. Many of these diseases start with microparasites, which are characterized by their ability to reproduce directly within an individual host. They are also characterized by their small size, short duration of infection, and the production of an immune response in infected and recovered individuals. Microparasites which damage hosts in the course of their association are recognized as pathogens. The level of the interaction and the extent of the resultant damage depends on both the virulence of the pathogen, as well as the host defenses. If the pathogen can overcome the host defenses, the host will be damaged and may not survive. If on the other hand the host defenses overcome the pathogen, the microparasite may fail to establish itself within the host and die.
Naegleria fowleri is a single-celled, protozoan pathogen found in fresh bodies of water and soil around the world (Skurie; Byrd 8). It thrives in the layer of sediment at the bottom of lakes and ponds. (Skurie). When living in soil, the N. fowleri, along with other protozoa microbes, clings to plant roots searching for bacteria (Byrd 261). This pathogen is a free-living pathogen classified as an amphizoic amoeba therefore it survives in a free state throughout soil and fresh water while having the ability to be a pathogen (Marciano-Cabral, “Immune”). It primarily seeks bacteria due to an inability to create food (Byrd 27); however, N. fowleri will attack a host if given the opportunity. In addition, it has been proven pathogens of the brain are often able to control the actions of their host to better suit the pathogen’s needs. An example may be to cause the host to have a high body temperature, wanting to stay warmer, or sleeping more often (Byrd 225). This microbe is typically found in the form of trophozoite, cyst, o...
The protozoan commonly known as the “water bear” is an extremophile that has engaged many in the scientific community. The Tardigrade is an invertebrate that has eight legs and comes in many shapes and sizes. This group has many adaptations such as cryptobiosis that allows it to survive in extreme environments. The Tardigrade can be found from land, to water, to sulfur springs, and to over 25 species found in the frozen tundra of Antarctica (Miller et al, 2001). To understand these creatures this paper will summarize the taxonomy, reproduction, food, and protective genetics, of the Tardigrades. The first section to this paper will examine is how these creatures are divided taxonomically.
Stokes, W.S. “Animals and the 3 R’s on Toxicology Research and Testing.” Human and Experimental Toxicology December 2015: 7. Academic Search Premier. Web. 14 February
Sophisticated methods of testing are now being applied to human cells in petri dishes. Human volunteers are also being used and micro-dose with samples so small that they do not cause adverse reactions. The argument exists that these alternative testing methods are not only more cost effective but also more relevant because they are conducted using human cells and specimens; a method that isn’t hindered by species differences. In addition, computer generated models are being used to produce virtual reconstructions in order to test toxicity.
...nvironmental Microbiology. New York: A John Wiley & Sons, Inc; 1992. pp. 125?156. Accessed December 2, 2013.
The second part of the article talks about how other scientists are excited to find out about extremophiles. It starts out with some history about how Carl Woese determined there is not two, but three domains of life, and how now, only recently, have scientists widely accepted his idea. Then it goes on to tell us about how these extremophiles are highly specialized for extreme conditions, and what some of these conditions are with the name they classify them as, depending on their environment. They continue with how these extremophiles may help us understand cancer a...
The duration of the experiment should be increased as the thermal death times of B. subtilis at 60, 70 and 80°C were unable to be determined within 110 minutes. The duration can be increased to 180 minutes so as to better investigate its thermal death times. If the presence of bacterial growth was still observed after 180 minutes of exposure, it can be assumed that B. subtilis is able to survive well in that temperature. An exposure time of one day can be carried out to confirm this assumption.
As many know, there are places on this earth where conditions are too inhospitable for humans to live. There are places with skull crushing depths, boiling water and high methane concentrations, where no human could survive. Survival in such hostile conditions was thought to be impossible for any organism; until the late 1960’s when bacterial microorganisms were found living in scalding thermal environments above 70 degrees Celsius, in Yellowstone National Park (Madigan & Marrs, 1997). These microorganisms were later termed extremophiles for their “love” of environments that are too hostile for other organisms to tolerate. Therefore, the capabilities and differences among extremophiles deserves a thorough investigation compared to the most adaptable species on the planet, humans.