Bacteria Classification By Gram Staining Essay Research free essay sample

Bacteria Classification By Gram Staining Essay, Research Paper Bacteria Classification By Gram Staining THE AMERICAN UNIVERSITY IN CAIRO BIOLOGY DEPARTMENT SCIENCE 453: Biology FOR ENGINEERS REPORT No.1 Presented By: Karim A. Zaklama 92-1509 Sci. 453-01 24/2/96 Aim: To prove a sample of research lab prepared bacteriums and categorize it harmonizing to Christian? s gm positive and gram negative categories and besides by sing it under a high powered microscope and oil submergences ; sort its form and note any particular features. Introduction: Bacteria was categorised into two groups in 1884 by the Danish Bacteriologist Christian, gm positive and gram negative by a staining technique where the ability to avoid de-coloration of Crystal Violet solution by intoxicant would render the class of gm positive, and gram negative if the bacteriums is de-coloured. This could be noted by the concluding coloring material of the bacteriums: a violet coloring material where Gram positive and a pink coloring material of the Safranin added pending the de-colouring procedure. We will write a custom essay sample on Bacteria Classification By Gram Staining Essay Research or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Materials: 1. Bacteria Sample 2. Microscope Slide 3. Gram Staining Kit and Wash Bottles a. Crystal Violet Solution b. Iodine Solution c. 95 % Ethyl Alcohol vitamin D. Safranin e. Distilled Water 4. Bibulous Blotting Paper 5. Microscope 6. Oil Procedure: A. Preparation: 1. Bacteria is cultivated on agar jelly in an brooder at 25? C for 24 hours. 2. Obtain a microscope slide and with a toothpick, smear a thin coat of the bacteriums sample onto the slide 3. Cover the smear with a bead Crystal Violet and go forth standing for 20 seconds 4. Wash off the discoloration with distilled H2O ; drain and smudge off the extra with boozy paper. 5. Use Gram? s Iodine on the vilification and leave to stand for 1 minute. 6. Drain the extra I and use 95 % Ethyl intoxicant for 20 2nd continuance or till the intoxicant runs clearly from the slide. 7. The vilification should rinsed for a few seconds with distilled H2O to halt the action of the intoxicant. 8. Drain and smudge off the extra with boozy 9. Introduce Safranin to the vilification and leave standing for 20 seconds. 10. Wash off the discoloration with distilled H2O ; drain and smudge off the extra with boozy paper. 11. Leave the slide to air prohibitionists. B. Examination: 1. Put the slide under microscope on low powered lens. 2. Travel the slide utilizing the setup until the sample can be seen as a fuzz under the microscope. 3. F ocus the lens to guarantee that there is a sample straight under the lens. 4. Move to higher powered lens, repeat measure 3. 5. Travel to higher powered lens, repeat measure 3 6. Move microscope aside and add Oil submergence, leave for a few seconds and re-examine the slide. Note Shape and coloring material and any other observations. Consequences and Observations: It was apparent by ocular scrutiny that the intoxicant was de-colouring or a least partly de-colouring the bacterium. The sample appeared a dark pink or shut to violet by the bare oculus ; a microscope was needed to guarantee consequences. Under the low powered microscope sunglassess of pink were noted. Under the medium power, the sunglassess were more clear but no form could be made out. Under the high powered microscope bunchs of pink rod ( B ) shaped bacteriums cells could be observed. Under Oil Immersion and high powered lens the cells could seen more separated out and therefore a clearer indicant of the pink coloring material, bacilli form and spores could be made out in the single cells. Decision: The Shape was noted as Bacilli ( Rod-like ) shaped cells ; a gm variable form, distinct in either Gram Negative or Gram positive bacteriums. The concluding coloring material of the cells were stained pink by the Safranin screening the de-coloration of the crystal violet turn outing the bacterium is of the gm negative category. Under oil submergence the cells became more thin and under the high powered lens of the microscope spores could be seen, as small bubbles, in the cells. This tells us that the bacterium was in its terminal province. The presence of spores in the bacterium at its terminal province Tells us that the bacteriums could be an old civilization. Old bacterium civilizations which are gm positive tend to de-colour, yet more easy than gram negative bacteriums. The velocity of de-coloration was non inspected really clearly therefore no farther decision could be reached, yet it is possible that this an old civilization of Bacilli shaped Gram Positive bacterium. Recommendation: It is recommended that the same sample be tested once more for de- colour ; concentrating on de-coloration velocity. If the de-coloration is fast so the sample is decidedly gram negative, slow de-coloration would state us it is gm positive. For future samples it would be recommended to maintain the bacterium sample for this specific trial for merely 16 hours every bit recommended to avoid the presence of old civilizations which are anomalous to this trial.

How To Calculate Avogadros Number Experimentally

How To Calculate Avogadro's Number Experimentally Avogadros number isnt a mathematically derived unit. The number of particles in a mole of a material is determined experimentally. This method uses electrochemistry to make the determination. You may wish to review the working of electrochemical cells before attempting this experiment. Purpose The objective is to make an experimental measurement of Avogadros number. Introduction A mole can be defined as the gram formula mass of a substance or the atomic mass of an element in grams. In this experiment, electron flow (amperage or current) and time are measured in order to obtain the number of electrons passing through the electrochemical cell. The number of atoms in a weighed sample is related to electron flow to calculate Avogadros number. In this electrolytic cell, both electrodes are copper and the electrolyte is 0.5 M H2SO4. During electrolysis, the copper electrode (anode) connected to the positive pin of the power supply loses mass as the copper atoms are converted to copper ions. The loss of mass may be visible as pitting of the surface of the metal electrode. Also, the copper ions pass into the water solution and tint it blue. At the other electrode (cathode), hydrogen gas is liberated at the surface through the reduction of hydrogen ions in the aqueous sulfuric acid solution. The reaction is:2 H(aq) 2 electrons - H2(g)This experiment is based on the mass loss of the copper anode, but it is also possible to collect the hydrogen gas that is evolved and use it to calculate Avogadros number. Materials A direct current source (battery or power supply)Insulated wires and possibly alligator clips to connect the cells2 Electrodes (e.g., strips of copper, nickel, zinc, or iron)250-ml beaker of 0.5 M H2SO4 (sulfuric acid)WaterAlcohol (e.g., methanol or isopropyl alcohol)A small beaker of 6 M HNO3 (nitric acid)Ammeter or multimeterStopwatchAn analytical balance capable of measuring to nearest 0.0001 gram Procedure Obtain two copper electrodes. Clean the electrode to be used as the anode by immersing it in 6 M HNO3 in a fume hood for 2-3 seconds. Remove the electrode promptly or the acid will destroy it. Do not touch the electrode with your fingers. Rinse the electrode with clean tap water. Next, dip the electrode into a beaker of alcohol. Place the electrode onto a paper towel. When the electrode is dry, weigh it on an analytical balance to the nearest 0.0001 gram. The apparatus looks superficially like this diagram of an electrolytic cell except that you are using two beakers connected by an ammeter rather than having the electrodes together in a solution. Take beaker with 0.5 M H2SO4 (corrosive!) and place an electrode in each beaker. Before making any connections be sure the power supply is off and unplugged (or connect the battery last). The power supply is connected to the ammeter in series with the electrodes. The positive pole of the power supply is connected to the anode. The negative pin of the ammeter is connected to the anode (or place the pin in the solution if you are concerned about the change in mass from an alligator clip scratching the copper). The cathode is connected to the positive pin of the ammeter. Finally, the cathode of the electrolytic cell is connected to the negative post of the battery or power supply. Remember, the mass of the anode will begin to change as soon as you turn the power on, so have your stopwatch ready ! You need accurate current and time measurements. The amperage should be recorded at one minute (60 sec) intervals. Be aware that the amperage may vary over the course of the experiment due to changes in the electrolyte solution, temperature, and position of the electrodes. The amperage used in the calculation should be an average of all readings. Allow the current to flow for a minimum of 1020 seconds (17.00 minutes). Measure the time to the nearest second or fraction of a second. After 1020 seconds (or longer) turn off the power supply record the last amperage value and the time. Now you retrieve the anode from the cell, dry it as before by immersing it in alcohol and allowing it to dry on a paper towel, and weigh it. If you wipe the anode you will remove copper from the surface and invalidate your work! If you can, repeat the experiment using the same electrodes. Sample Calculation The following measurements were made: Anode mass lost: 0.3554 grams (g)Current(average): 0.601 amperes (amp)Time of electrolysis: 1802 seconds (s) Remember:One ampere 1 coulomb/second or one amp.s 1 coulombThe charge of one electron is 1.602 x 10-19  coulomb Find the total charge passed through the circuit.(0.601 amp)(1 coul/1amp-s)(1802 s) 1083  coulCalculate the number of electrons in the electrolysis.(1083 coul)(1 electron/1.6022 x 1019coul) 6.759 x 1021  electronsDetermine the number of copper atoms lost from the anode.The electrolysis process consumes two electrons per copper ion formed. Thus, the number of copper (II) ions formed is half the number of electrons.Number of Cu2  ions  ½ number of electrons measuredNumber of Cu2  ions (6.752 x 1021  electrons)(1 Cu2  / 2 electrons)Number of Cu2  ions 3.380 x 1021  Cu2  ionsCalculate the number of copper ions per gram of copper from the number of copper ions above and the mass of copper ions produced.The mass of the copper ions produced is equal to the mass loss of the anode. (The mass of the electrons is so small as to be negligible, so the mass of the copper (II) ions is the same as the mass of copper atoms.)mass loss of electrode mass of Cu2  ions 0.3554 g3.380 x 1021  Cu2  ions / 0.3544g 9.510 x 1021  Cu2  ions/g 9.510 x 1021  Cu atoms/g Calculate the number of copper atoms in a mole of copper, 63.546 grams.Cu atoms/mole of Cu (9.510 x 1021  copper atoms/g copper)(63.546 g/mole copper)Cu atoms/mole of Cu 6.040 x 1023  copper atoms/mole of copperThis is the students  measured  value of  Avogadros  number!Calculate percent error.Absolute error: |6.02 x 1023  - 6.04 x 1023  | 2 x 1021Percent error: (2 x 10 21 / 6.02 x 10 23)(100) 0.3 %

American beauty and Existentialism Movie Review

American beauty and Existentialism - Movie Review Example The continual struggle of Lester Burnham regarding the meaning of life eventually endows him with the freedom to assume total responsibility for his life, thereby taking the onus to give a meaning to his life, which though did not affiliate to any organized and systematic philosophical discipline is of immense importance and concern, so far as the life of Lester Burnham is concerned. Hence, eventually in the climax, Lester Burnham arrives at a meaningful conclusion that corroborates the essential existential theme that any valid philosophical quest ought to stand on a foundation comprising of the actual experiences of an individual. The eventual demise of Lester Burnham is not only satisfactory and well deserved in the context of his individual struggle, but is also indicative of the possibility of soliciting happiness by proactively engaging in an existential crisis. The existential themes inherent in the movie American Beauty could only be grasped by having a relevant insight into the actual plot and contexts. The central character in the movie that is Lester Burnham is shown to be up against a midlife existential crisis. In the movie Lester Burnham is shown to be a middle aged American male who is both a husband and a father. Lester is shown to be trapped in a marriage that is of no relevant meaning or interest to him. He happens to be the father of a daughter who actually seems to hate him. Lester is also shown to be trapped in a job that not only devoid of any motivation or interest, but also happens to be morally and ethically debasing and from which Lester Burnham intends to escape for the sake of personal peace and well being. It is only after Lester Burnham gets attracted to her daughter’s young and beautiful friend that he begins to assume responsibility for his life, thereby getting actively engaged in asking questions and making decisions that lead to his eventual sad but personally edifying death. In that context, the movie American Beauty f acilitates a deep insight into the actual motivations behind the so called modern life and the commensurate human struggle to seek meaning and personal contentment. The movie presents to the viewers the varied existential themes marking the contemporary life through the existential struggle of the central character Lester Burnham, at the same time shedding light on the vacuity and inanity of the individuals and organizations surrounding Lester Burnham. The plot of the movie thereby serves two purposes, one to unravel the absurdity and ludicrousness hidden behind the conformist notions of life, and second the possibility of seeking happiness and fulfillment in the small things marking the human existence. One existential theme that continually pops up while being engaged in the unraveling of the seemingly banal and mundane life of Lester Burnham is that of authenticity. In a quest for personal meaning and goal, the existential struggle engaged into by the central character that is Le ster Burnham, the character is shown to be living Sartre’s notion of authenticity, thereby practically symbolizing the fact that â€Å"authenticity implies the assumption of one’s moral responsibility, the recognition that one has to decide what is good (Schilpp 96).†Through his existential struggle, Lester Burnham actually establishes that authenticity is possible that even while being numbly engaged in an existential struggle, there does is a personal unity of consciousness, a personal capacity to be a proactive