Identity crisis (joy luck club Essay Example For Students

Identity crisis (joy luck club Essay Identity Crisis(Joy Luck Club)Every person comes to a point in their life when they begin to search for themselves and their identity. Usually it is a long process and takes a long time with many wrong turns along the way. Family, teachers, and friends all help to develop a person into an individual and adult. Parents play the largest role in evolving a person. Amy Tan, author of the Joy Luck Club, uses this theme in her book. Four mothers have migrated to America from China because of their own struggles. They all want their daughters to grow up successful and without any of the hardships they went through. One mother, Suyuan, imparts her knowledge on her daughter through stories. The American culture influences her daughter, Jing Mei, to such a degree that it is hard for Jing Mei to understand her mothers culture and life lessons.Yet it is not until Jing Mei realizes that the key to understanding who her mother was and who she is lies in understanding her mothers life. Jing Mei spends her American life trying to pull away from her Chinese heritage, and therefore also ends up pulling away from her mother. Jing Mei does not understand the culture and does not feel it is necessary to her life. When she grows up it is not fashionable to be called by your Chinese name (26). She doesn’t use, understand, or remember the Chinese expressions her mother did, claiming she can never remember things she didn’t understand in the first place (6). Jing Mei begs her mother to buy her a transistor radio, but her mother refuses when she remembers something from her past, asking her daughter Why do you think you are missing something you never had? (13) Instead of viewing the situation from her mothers Chinese-influenced side, Jing Mei takes the American materialistic viewpoint and sulks in silence for an hour (13). By ignoring her mom and her moms advice, Jing Mei is also ignoring some of the similarities between her and her mother. Suyuan has also reje cted some of the Chinese traditions. Suyuan rejects the women-repressive Chinese traditions when she tells her daughter that she believed you could be anything you want to be in America (141). Suyuan continually tells Jing Mei her Kweilin story as a child, the story of the origins of the Joy Luck Club as well as her mothers past hardships. Yet despite the importance of the story and the events constituting the story to Suyuan, Jing Mei never thought her mothers Kweilin story was anything but a Chinese fairy tale (12). The story would have the same meaning to Jing Mei as if she were being told the story of Sleeping Beauty, or some other American bedtime story. When Jing Mei recognizes the similarities between her mother and herself she begins to understand not only her mother but herself as well. There are subtle connections and likenesses from the beginning between Jing Mei and her mother that Jing Mei does not see. The book commences with Jing Mei taking her mothers place at the mah jong table, creating a similarity between them from the beginning. Suyuan dies two months before the start of the book, and therefore is not able to tell the stories. Jing Mei has learned and must tell her stories in her place, forming another parallelism between mother and daughter. Because Suyuan is dead, Jing Mei must act in place of her mother when she goes to meet her Chinese sisters in China. Throughout the book Jing Mei takes the place of Suyuan, showing she and her mother have a unique link even with the barrier of the living world. Jing Mei finally begins to realize her identity and past when she travels in place of her mother to China to meet her two twin sisters. Suyuan had to make the hard decision to leave her twin babies on the side of the road in hopes some kind stranger would tak e them in, that way she would not have to see them die. Suyuan searches for her babies all through her life in America, sending multitudes of letters; they finally get in touch with her two months after she has died. Because her mother is not alive to meet her children, Jing Mei takes her place and the trip enables her to finally recognize her Chinese ancestry. The minute she enters China she feels different and can realize that she is becoming Chinese (306). At fifteen Jing Mei believed she was only as Chinese as her Caucasian friends (306). Yet her mother counters thoughts, telling her: Once you are born Chinese, you cannot help but feel and think Chinese (306). Once in China Jing Mei decides her mother was right and she has never really known what it meant to be Chinese (307). She has never understood her mother or her heritage. This trip is the connecting link to understanding her life. She begins to feel natural in China, thinking to herself on the train: I am in China†¦ I t feels right (312). Jing Mei sees the landscape, the people, the histories, and the families in China and sees where her mother was speaking from all of those years. She knows a little percent of her mother know (15). It becomes obvious to Jing Mei to see what part of her is Chinese; it is in her family, in her blood (331). Jing Mei finally realizes herself when she travels to China, trying to connect with her mother and searching for her identity. The longer she stays in China, the more connected Jing Mei feels to her mother, the more she feels at home, and the more she understands what her mother was trying to teach her. At last when Jing Mei embraces her sisters for the first time at the airport, and they look at the Polaroid so view their similarities, Jing Mei realizes the part of her that is Chinese is her family. She must embrace the memory of her dead mother to grasp that part of her identity.

Origins And History Of The Electoral College Essays -

Origins And History Of The Electoral College Origins and History of the Electoral College In order to appreciate the reasons for the Electoral College, it is essential to understand its historical context and the problem that the Founding Fathers were trying to solve. They faced the difficult question of how to elect a president in a nation that: Origins of the Electoral College The Constitutional Convention considered several possible methods of selecting a president. One idea was to have the Congress choose the president. This idea was rejected, however, because some felt that making such a choice would be too divisive an issue and leave too many hard feelings in the Congress. Others felt that such a procedure would invite unseemly political bargaining, corruption, and perhaps even interference from foreign powers. Still others felt that such an arrangement would upset the balance of power between the legislative and executive branches of the federal government. A second idea was to have the State legislatures select the pres ident. This idea, too, was rejected out of fears that a president so beholden to the State legislatures might permit them to erode federal authority and thus undermine the whole idea of a federation. A third idea was to have the president elected by a direct popular vote. Direct election was rejected not because the Framers of the Constitution doubted public intelligence but rather because they feared that without sufficient information about candidates from outside their State, people would naturally vote for a favorite son from their own State or region. At worst, no president would emerge with a popular majority sufficient to govern the whole country. At best, the choice of president would always be decided by the largest, most populous States with little regard for the smaller ones. Finally, a so-called Committee of Eleven in the Constitutional Convention proposed an indirect election of the president through a College of Electors. The First Design In the first design of the Ele ctoral College (described in Article II, Section 1 of the Constitution): Each State was allocated a number of Electors equal to the number of its U.S. Senators (always 2) plus the number of its U.S. Representatives (which may change each decade according to the size of each State?s population as determined in the decennial census). This arrangement built upon an earlier compromise in the design of the Congress itself and thus satisfied both large and small States. The manner of choosing the Electors was left to the individual State legislatures, thereby pacifying States suspicious of a central national government. Members of Congress and employees of the federal government were specifically prohibited from serving as an Elector in order to maintain the balance between the legislative and executive branches of the federal government. Each State?s Electors were required to meet in their respective States rather than all together in one great meeting. This arrangement, it was thought, would prevent bribery, corruption, secret dealing, and foreign influence. In order to prevent Electors from voting only for a favorite son of their own State, each Elector was required to cast two votes for president, at least one of which had to be for someone outside their home State. The idea, presumably, was that the winner would likely be everyone?s second favorite choice. The electoral votes were to be sealed and transmitted from each of the States to the President of the Senate who would then open them before both houses of the Congress and read the results. n The person with the most electoral votes, provided that it was an absolute majority (at least one over half of the total), became president. Whoever obtained the next greatest number of electoral votes became vice president?an office which they seem to have invented for the occasion since it had not been mentioned previously in the Constitutional Convention. In the event that no one obtained an absolute majority in the Electoral College or in the event of a tie vote, the U.S. House of Representatives, as the chamber closest to the people, would choose the president from among the top five contenders. They would do this (as a further concession to the small States) by allowing each State to cast only one

The Feedback Draft Essay Sample - Uses it to Write Better!

The Feedback Draft Essay Sample - Uses it to Write Better!The feedback draft essay sample is an important and very useful tool that every student needs to have on their academic portfolio. A quick assessment of what the student has written will allow a teacher to judge if the student is ready for the written part of the assignment.A good feedback draft essay sample is a lot more than just a little bit of writing that does not relate well to the topic. A student can get into trouble if he/she does not know what to write in the student feedback portion of the written test.The best feedback draft essay samples will show a student exactly how to construct a written piece that connects in an interesting way with the topics of the essay. Most students will feel great when they do well, so the teacher can use that as a motivating factor to get them to write better. If the student fails a test, it will also cause a negative feeling for that student and will make them work even harder.A good feedback essay sample will show students what kind of a piece they should write. Usually a short response will be the best. Students can take the feedback to sample and apply it in different types of essays and short responses.The feedback draft essay sample is helpful for students because it makes it easy for them to write about something they are already familiar with. If a student has studied the bible, for example, a feedback essay can show him how to write the simple short response like a bible story. There are many ways that a student can be encouraged to write the feedback response properly.One way is to encourage a student to think out of the box and think up a way to write a response that connects with his/her knowledge of the subject. This will help the student to write a powerful and exciting essay that a teacher will be proud to have as his/her own.If a student cannot figure out what to write in the response section, the feedback draft can also show him how to write a re sponse with his own idea. For example, the student might write about trying to figure out what someone else is talking about when they talk about something they know very little about. This is an excellent way to go when writing the short response portion of the assignment.The feedback draft essay sample is an extremely valuable tool for students that are struggling in school. Students can use this tool to come up with a number of interesting essays that can inspire them and get them excited about getting better at writing.

Free Essays on A Midsummer Nights Dream

In the ancient city of Athens a wedding is about to take place between Theseus, duke of Athens, and Hippolyta, the Amazon warrior queen who he had won. They meet in the duke's palace to discuss their marriage festivities. Suddenly, Egeus storms in, extremely upset. He wants his daughter, Hermia, to marry Demetrius, who is in love with her. Hermia, however, is in love with Lysander and refuses to give in to her father's demands. The two men and the woman they both love state their case before the duke. Theseus explains that Athenian law is on the side of the father: Hermia must give into his wishes, not follow her own desire. Also, Hermia must either obey the law, remain a virgin and enter a nunnery, or die! Hermia is given until the next new moon the wedding day of Theseus and Hippolyta to make her decision. She and Lysander secretly plan, instead, to run from Athens and live outside of town with an aunt of Lysander's. Helena, arrives, she is in love with Demetrius, but he doesnâ⠂¬â„¢t love her. In the house of Quince, a carpenter, several Athenian workingmen meet to discuss their plans to present a play as entertainment for the wedding of the duke. Quince, Snug, Bottom, Flute, Snout, and Starveling have decided on a play entitled "The most lamentable comedy, and most cruel death of Pyramus and Thisby." Parts are assigned to each player, but only after Bottom, shows how he could play all the parts himself. They agree to rehearse the following evening in a wood outside of town. Next the players are in an entirely different order. They are Oberon, the king of the fairies, his queen, Titania, and Puck (or Robin Goodfellow), a fairly like attendant of the king. Oberon and Titania have been fighting over the possession of a young Indian boy that both want, but the Queen will not hand him over. Oberon, with the aid of Puck, plans his revenge on Titania. He will drop the juice of a magic flower into the eyes of his sleeping queen. When ... Free Essays on A Midsummer Night's Dream Free Essays on A Midsummer Night's Dream A Midsummer Night’s Dream In the beginning of the play, Hermia was refusing to marry a man named Demetrius because she was in love with another man named Lysander. Hermia and Lysander planned to run away into the forest together the next day so they could get married. In the forest, the king of the fairies tells another fairy named Puck to get a flower that makes you fall in love with the first person you see. Puck started anointing everyone with the magical flower, but he anoints all of the wrong people. Both Lysander and Demetrius end up falling in love with Helena and they all start fighting with each other because Helena just thinks they are leading her on. He also turned Bottom into a donkey and made the queen of the fairies fall in love with him. The king of the faries puts all of them to sleep to fix things while the spell wears off. They all wake up loving the right people and then Demetrius marries Helena and Lysander marries Hermia. I liked the play a lot because it wasn’t too hard to follow and it was extremely funny. My favorite parts were when Hermia, Helena, Demetrius, and Lysander were all under the spell and arguing, the play within the play, and the dancing at the end. I thought the celtic music was one of the best parts. I liked it a lot because the actors all came down in the audience and were dancing. I thought it was a good ending to a really good play.... Free Essays on A Midsummer Night's Dream In the ancient city of Athens a wedding is about to take place between Theseus, duke of Athens, and Hippolyta, the Amazon warrior queen who he had won. They meet in the duke's palace to discuss their marriage festivities. Suddenly, Egeus storms in, extremely upset. He wants his daughter, Hermia, to marry Demetrius, who is in love with her. Hermia, however, is in love with Lysander and refuses to give in to her father's demands. The two men and the woman they both love state their case before the duke. Theseus explains that Athenian law is on the side of the father: Hermia must give into his wishes, not follow her own desire. Also, Hermia must either obey the law, remain a virgin and enter a nunnery, or die! Hermia is given until the next new moon the wedding day of Theseus and Hippolyta to make her decision. She and Lysander secretly plan, instead, to run from Athens and live outside of town with an aunt of Lysander's. Helena, arrives, she is in love with Demetrius, but he doesnâ⠂¬â„¢t love her. In the house of Quince, a carpenter, several Athenian workingmen meet to discuss their plans to present a play as entertainment for the wedding of the duke. Quince, Snug, Bottom, Flute, Snout, and Starveling have decided on a play entitled "The most lamentable comedy, and most cruel death of Pyramus and Thisby." Parts are assigned to each player, but only after Bottom, shows how he could play all the parts himself. They agree to rehearse the following evening in a wood outside of town. Next the players are in an entirely different order. They are Oberon, the king of the fairies, his queen, Titania, and Puck (or Robin Goodfellow), a fairly like attendant of the king. Oberon and Titania have been fighting over the possession of a young Indian boy that both want, but the Queen will not hand him over. Oberon, with the aid of Puck, plans his revenge on Titania. He will drop the juice of a magic flower into the eyes of his sleeping queen. When ... Free Essays on A Midsummer Night's Dream A Midsummer Night’s Dream, written by William Shakespeare is a lively comedy. It takes place in the realm of both the mortals and the fairies. The realm of the mortals is often referred to as the â€Å"real world† and the realm of the fairies as the â€Å"fairy world.† Both worlds are presented with problems. Neither world is faultless. Egeus commands Hermia to marry Demetrius. However, Hermia loves Lysander and the two lovers decide to run away. Helena is in love with Demetrius, who does not return her love. Helena, who is aware of the two lovers’ plan, tells the plan to Demetrius. This is the beginning of the comedic complications between the love affairs of Hermia, Helena, Lysander, and Demetrius. The fairy world has problems of its own. Oberon, the king of fairies, is jealous of Titania’s Indian Boy. Along with these stories, there is a play that is being rehearsed for the Duke. It is the play, â€Å"Pyramus and Thisbe,† act ed by Nick Bottom and Francis Flute as the two characters, respectfully. Puck’s mischief stirs up confusion for the four mortal lovers and Titania falls in love with a Nick Bottom, who has been transformed into a donkey. However, when the two worlds come together, the fairy world seems to control the real world. Although, Theseus believes he has ultimate power and control over Athens, the conflicts of the real world can not be resolved without the magical powers of the fairy world. The story of A Midsummer Night's Dream is a comedy. Shakespeare was a playwright during the Elizabethan era, when most plays were either comedy or tragedy. It wasn't the lines read or story that made a play tragic or comedic. Comedy plays were distiniguishable by their costume, stage, and make-up. The magical and fairy realm setting, the costumes of the fairies, and Nick Bottom wearing a donkey head would constitute this play as a comedy. The story of A Midsummer's Night Dream begins with an introduction ...

Biochemical Action of Bacteria

To observe the growth of different bacteria species in term of structures and its morphology based on different chemical substance applied. 3. To observe physiological and immunological properties utilized by different species of bacteria. INTRODUCTION: Bacteria biochemical testing can determine the types and numbers in terms of colony forming units of bacteria present in a sample of different chemical. The testing could be focused on a specific type of bacteria, medical bacteria or a broad range of environmental bacteria. Since bacteria are present in virtually any environment, it’s important to be clear why the testing is being performed. The more specific the testing is the better and the easier it is to interpret the results. Numbers and types of bacteria that should be a cause for concern depends upon several factors, including the type of bacteria present and the type of samples. Escherichia coli  are one of the main species of bacteria living in the lower intestines of mammals. E. coli  can be found in the intestinal tract of warm-blooded animals. The presence of  E. coli  in foods is considered to be an indication of fecal contamination. Staphylococcus  organisms are commonly found in the environment. Several species of  Staphylococcus  are found on the skin, intestines, nasal passages, etc. of warm-blooded animals. Some species of  Staphylococcus, particularly  Staphylococcus aureus  can be pathogenic are capable of causing illness. Pseudomonas aeruginosa is widely distributed in soil, water and plants. It survives in hot tubs, whirlpools, contact lens solution, sinks and showers. It can cause a number of opportunistic infections including infections of the skin, external ear canal and of the eye. Nitrifying bacteria recycle organic nitrogenous materials from ammonium (the endpoint for the decomposition of proteins) to nitrates. Their presence can indicate that the water may have been polluted by nitrogen-rich organics from sources such as compromised septic tanks, sewage systems, industrial and hazardous waste sites and is undergoing an aerobic form of degradation. The presence of denitrifying bacteria can indicate that the water has been polluted by nitrogen-rich organics from sources such as compromised septic tanks, sewage systems, industrial and hazardous waste sites. MATERIALS: 1. Nutrient broth cultures of Escherichia coli . Nutrient broth cultures of Serratia marcescens 3. Nutrient broth cultures of Salmonella typhimurium 4. Nutrient broth cultures of Bacillus subtilis 5. Nutrient broth cultures of Klebsiella spp. 6. Nutrient broth cultures of Streptococcus spp. 7. Nutrient broth cultures of Staphylococcus aurieus 8. Nutrient broth cultures of Proteus vulgaris 9. Nutri ent broth cultures of Pseudomonas fluorescens 10. Parafilm tape 11. Inoculating loops 12. Gloves 13. Incubator 14. Nutrient agar plate 15. Nutrient agar slants 16. Starch agar plates 17. Gelatine agar plates 18. 2 tubes Clark’s-Lub medium (MR-VP medium) 19. Tryptone broth 20. 3 Kigler’ slant 21. 5 tubes nitrate broth ( 0. 1% KNO3) 22. 5 urea broth 23. Tube containing 10ml of sterile saline 24. Glucose broths with Durham tubes and phenol red indicator 25. Lactose broths with Durham tubes and phenol red indicator 26. Sucrose broths with Durham tubes and phenol red indicator 27. Gram’s iodine 28. Kovac’s indol reagent 29. Mercuric chloride solution 30. KOH-creatine solution or 40% KOH 31. FR reagent 32. Nessler’s reagent PROCEDURE: A. CARBOHYDRATE METABOLISM 1. Fermentation of sugars Materials: 1. Glucose broths with Durham tubes and phenol red indicator 2. Lactose broths with Durham tubes and phenol red indicator 3. Sucrose broths with Durham tubes and phenol red indicator 4. 18 hour nutrient broth cultures of E. coli and S. typhimurium Procedure: 1) The small bottles of different sugars were inoculated with a loopfuls of E. coli and Salmonella spp. 2) The tubes were labelled and incubate at 37oC for 24 hours 3) All observations were recorded for presence of acid or gas production. 2. Hydrolysis of starch Materials: 1. Starch agar plates 2. Broth agar cultures of B. subtilis and E. coli Procedure: 1) Starch plate was streaked with E. coli in for sections and repeated for B. ubtilis bacteria in other starch plate. 2) The plates were secured with parafilm, labelled and inoculated at 37oC for 24 hours. The following day 1) The plates were tested for starch hydrolysis by flooding the pates with Gram’s iodine. 2) The plates were examined and the colonies that showed clear uncoloured zones in contrast with the blue-black background of the starch-iodine complex were noted. 3) The extent of the zones of hydrolysis indicated either the reddish colour zones were seen. 4) All results and observations were recorded. B. PROTEIN AND AMINO ACID METABOLIM 1. Indole test Materials: 1. Broth cultures of B. ubtilis, E. coli, and S. typhimurium 2. 3 tubes of tryptone broth 3. Kovac’s indole test reagent Procedures: 1) The peptone water was inoculated with a loopfuls of the test organism. 2) The tube was labelled and incubated for 24 hours. The following day 1) The tubes were added with a few drops of Kovac’s indole reagent (dimethylaminobenzaldehyde) 2) The red or dark color indicates the presence of indole. 4. Hydrogen sulphide Materials: 1. Broth cultures of B. subtilis, E. coli, and S. typhimurium 2. 3 Kigler’s slant Procedures: 1) The Kigler’s slant was inoculated with a loopfuls of the test organism by the stab method. ) The tube was labelled and incubated for 24 hours. The following day 3) Th e Kigler’ slant was observed for production of H2S where the black precipitate along the line of growth in the Kigler’s slants indicated the H2S have been produced. 4) The observations were recorded. 3. Gelatine hydrolysis test Materials: 1. Broth cultures of B. subtilis, E. coli, and S. typhimurium 2. Gelatine agar plates 3. Mercuric chloride solution Procedures: 3) The gelatine agar plates were inoculated with a loopfuls of the test organism with a single streak at the centre of the plates. ) The plates were secured with parafilm, labelled and incubated for 24 hours. The following day 5) The plates were flooded with mercuric chloride solution. 6) The medium become opaque in regions that still contain gelatine and clear regions where gelatine has been hydrolysed. C. VOGES-PROSKAUER TEST Materials: 1. Broth cultures of E. coli, and Klebsiella spp. 2. 2 tubes of Clark-Lub’s medium (MR-VP medium) 3. KOH-creatine solution Procedures: 1) The tubes of Clark-Lubâ€⠄¢s medium (MR-VP medium) were inoculated with a loopfuls of the test organism. 2) The tubes were labelled and incubated for 24 hours. The following day 1) The tubes were tested with Voges-Proskauer test. 2) The 0. 5ml of KOH-creatine solutuin was addd. 3) The tube was shaked vigorously for 30 seconds. 4) The red or pink color indicates the presence of acetoin. D. CATALASE TEST Materials: 1. Broth cultures of Streptococcus spp. and Staphylococcus aureus. 2. Nutrient agar slant Procedures: 1) The nutrient agar slant was inoculated with a loopfuls of the test organism. 2) The tube was labelled and incubated for 24 hours. The following day 1) The tubes were tested with catalase test by adding several drops of a 5% solution of hydrogen peroxide. ) The vigorous bubbling indicates the presence of oxygen. E. NITRATE REDUCTION TEST Materials: 1. Broth cultures of E. coli, Proteus vugaris, Serratia marcescens, Pseudomonas fluorescens. 2. 5 tubes containing nitrate broth (0. 1% KNO3) 3. Nitrate test reagent Procedures: 1) The nitrate broth was inoculated with a loopfuls of the test organism. 2) The tube was labelled and incub ated for 24 hours. The following day 1) The tubes were tested with 1ml of Follet and Ratcliff’s (FR reagent) 2) The orange or brown color indicates the presence of nitrate. 3) The absent of nitrate indicates that: a. There has been no nitrate reduction b. The reduction has proceeded beyond that nitrate stage. 4) The absent of orange or brown color were further tested with small amount of cadmium to the tube. If nitrate still present, it will be catalytically change to nitrate which will then reacts with the FR reagent in the tube. 5) In the absent of a positive nitrate result, the bubbles f H2 gas was observed in the Durhams tube OR 6) The samples were tested with 1ml of Nessler’s reagent. The brown or orange color indicates the presence of ammonia. F. UREASE TEST Materials: 1. Broth cultures of E. coli, P. vugaris, S. arcescens, P. fluorescens. 2. 5 urea broth with indicator Procedures: 1) The urea broth was inoculated with a loopfuls of the test organism. 2) The tube was labelled and incubated for 24 hours. The following day 1) The urease-positive organism produced in intense red/purple coloration of the medium after incubation. 2) All observations were recorded. RESULTS AND OBSERVATION: Test| Observation(After 24 hours incubation)| Description| A. Carbohydrate Test 1. Fermentation of starchDurham tubes and phenol-red indicator. 2. Hydrolysis of starch| Glucose: Lactose: Sucrose: Starch agar plates:B. ubtilisE. coli| * Positive result for E. coli as tube turn yellow * Positive result for S. typhimium as tube turn yellow * Positive result for E. coli as tube turn yellow * No gas produced by S. typhimium because the tube turns red. * No gas produced by E. coli because the tube is slightly red. * Positive result for S. typhimium as tube turn yellow * Positive zone of clearing. * Negative zone of clearing. | B. Protein And Amino Acid Metabolism 1. Indole test 2. Hydrogen disulphide 3. Gelatine hydrolysis test| Tryptone broth:B. subtilisE. coli. S. typhimuriumKigler’s slant:B. subtilisE. oli. S. typhimuriumGelatine agar plates:B. subtilisE. coli. S. typhimurium| * Negative Indole tests no color change. * Bright fuschia at the interface is positive test for Indole . * Negative Indole tests no color change. * Black precipitate form shows positive sulphur reduction. * Negative reaction. * Positive reaction forming the black precipitate. * Positive hydrolysis of gelatine into amino acid to be used as nutrients/gelatinase. * Negative hydrolysis of gelatine. * Negative hydrolysis of gelatine| C. Voges- Proskaeur’s Test| MR-VP medium:E. coli. Klebsiella spp. | * Negative results of E. oli * Positive results Klebsiella spp. | D. Catalase Test| Nutrient agar slant:S. aureusStreptococcus spp. | S. aureus * Positive catalase reaction because present of bubblesStreptococcus spp. * Negative catalase reaction no bubbles present. | E. Nitrate Reduction Test| Nitrate broth:E. coliP. vulgarisS. marcescensP. fluorenscens| * No color change after denitrification of ammonia. * No color change after denitrification of ammonia. * Turns red. Positive nitrate test shows nitrate reductase present. * Turns red but negative catalase test. | F. Urease Test| Urea broth:E. coliP. vulgarisS. marcescensP. luorenscens| * Negative urease test because the tube remain purple. * P. vulgaris show positive urease test from yellow to pinkish. * S. marcescens show negative urease test because the color remain purple. * P. fluorenscens show negative urease test because the color remain purple. | DISCUSSION: Biochemical tests of bacteria oobjectively to test the metabolism of carbohydrate and related products of different bacteria species, test specific breakdown of products through color changes and gas produced. Besides that, the ability of bacteria utilizes a specific substance and the metabolism of protein and amino acid by bacteria. A. CARBOHYDRATE TEST Carbohydrate is an organic compound that consists of only carbon, hydrogen and oxygen which is basically the major carbon source of most organisms. Specific carbohydrate can be fermented by organism that incorporated in a medium producing red or acid with gas. Pinkish red color shows positive results where acidic content formed in the tube because carbon dioxide realised if fermentation occur. Negative catabolism of carbohydrate shows by yellow to colourless of Durham’s tube as the solution remain alkaline in the absent of carbon dioxide gas. Gas production can be seen as bubbles in Durham’s tube. Central carbohydrate metabolism or the breakdown of sugars into smaller compounds accompanied by the production of ATP and reduction of coenzymes, follows one of several pathway. Carbohydrate utilization and fermentation will be assessed by growing cells without shaking (aeration) in defined media containing a single carbohydrate. Acid products of sugar fermentation will cause a noticeable color change in the pH indicator included in the medium. Sugar fermentation does not produce alkaline product, however non-fermentative hydrolysis of amino acids in the peptone, present in most fermentation media, may give an alkaline reaction, which will also cause a color change in the pH indicator. Gas production, H2 in particular, can be determined by placing a small, inverted Durham tube in the test medium. If gas is produced, it is trapped in the Durham tube and can be seen as a bubble. Hydrogen sulfide (H2S) is produced by bacterial anaerobic degradation of the two sulfur-containing amino acids, cysteine and methionine. Hydrogen sulfide is released as a by-product when carbon and nitrogen atoms in the amino acids are consumed as nutrients by the cells. Under anaerobic conditions the sulfhydryl (-SH) group on cysteine is reduced by cysteine desulfurase. Ferrous ammonium sulfate-indicator. H2S reacts with ferrous sulfate forming the black precipitate Sodium thiosulfate is reduced to sulphite/thiosulfate The Kligler’s Iron test is used to detect liberation of H2S gas by bacteria growing on an excess of these sulfur-containing amino acids. The agar contains high levels of peptones or sources of cysteine and methionine and ferrous sulfate as an indicator. When H2S is produced, the ferrous ion reacts with it to give ferrous sulfide, an insoluble black precipitate. In starch hydrolysis test Iodine must be on the plate to visualize the zone of clearing surrounding the bacteria. This zone indicates starch was broken down to dextrins, maltose, and glucose. B. PROTEIN AND AMINO ACID METABOLIM Indole test measures the ability of bacteria to split indole from tryptophan molecule but in term of biochemistry, Indole test is one of the metabolic degradation products of the amino acid tryophan. Bacteria that possess the enzyme trytophanase are capable of hydrolysing and deaminating tryptophan with the production of Indole, pyruvic acid and ammonia. Positive reaction showed by E. coli, P. vulgaris and negative results observed in Klebsiella and Salmonella from observation in the Indole test. Development of fuchsia red color at the interface of the reagent and the broth within seconds after adding the reagent is indicative of the presence of Indole and is a positive test. Kovac’s reagent detects if tryptophan has been hydrolyzed to indol or tryptophanase. Gelatin is the protein derived from the animal protein collagen, has been used as a solidifying agent in food for a long time besides nutrient gelatine as an early type of solid growth medium. One problem is that many bacteria have the ability to hydrolyze or liquefy the gelatin. This gelatin liquefaction ability forms the basis for this test. C. VOGES-PROSKAUER TEST The production of acetoin by bacteria is perform through Voges Proskauer Test to determine the ability of the organisms to produce neutral end product acetyl methyl carbinol (acetoin) from glucose fermentation. Negative results gained from E. coli meanwhile positive reaction gives by. Changing of color to red pinkish color at the surface of the medium indicated positive results and yellow color at the surface of the medium show negative reaction. The KOH reagent should not be excessively added to the sample because excess KOH may mask weak VP positive reactions. The MR test will be positive for organisms that have complete pathways for mixed acid fermentation. The Voges-Proskauer (VP) test determines whether a specific neutral metabolic intermediate, acetoin, has been produced instead of acid from glucose. Acetoin is the last intermediate in the butanediol pathway, which is a common fermentation pathway in B. subtilis. The tests are complementary in the sense that often a bacterium will give a positive reaction for one test and a negative reaction for the other. The three possible patterns of results where the acetoin fermentation pathway, detected by the VP test, two molecules of pyruvate condense and two molecules of CO2 are released. The 4 carbon intermediate that is formed, acetoin, contains a carbonyl group. The acetoin acts as a terminal electron acceptor with the carbonyl group being reduced to a hydroxyl group. The reduced product, butanediol, is excreted by the bacteria and acetoin is oxidized to diacetyl by alkaline -naphthol, which forms a red complex with creatinine. D. CATALASE TEST Catalase is present in most cytochrome containing aerobic and facultative anaerobic bacteria except Streptococcus spp. Hydrogen peroxide forms as one of the oxidative end product of aerobic carbohydrate metabolism. If hydrogen peroxide allowed accumulating in the bacterial cells it becomes lethal to the bacteria. Catalases help in converting H2O2 to water and oxygen. In the catalase test performed, Streptococcus spp gives negative reaction as for S. aureus, the positive reaction occurred. One of the by-products of oxidation-reduction in the presence of O2 during aerobic respiration is hydrogen peroxide (H2O2). This compound is highly reactive and must be degraded in the cytoplasm of the cell producing it. It can be especially damaging to molecules of DNA. Most aerobes synthesize the enzyme catalase, which breaks down H2O2 into water and oxygen. The O2 gas is identified by the production of bubbles from a concentrated cell suspension. The test for catalase is simple and usually very reliable. It is a major method of distinguishing between Staphylococcus (catalase positive), Streptococcus (catalase negative), and Enterococcus (catalase negative), although some strains of Enterococcus faecalis may be positive. Catalase production is generally associated with aerobic organisms, since H2O2 is a toxic by-product of aerobic growth, but not always. E. NITRATE REDUCTION TEST Nitrate reduction test basically test the ability of organism to reduce the nitrate to nitrites of free nitrogen gas. In order to determine either the bacteria can reduce nitrate, the test organism is inoculated into nitrate reduction broth, undefined medium that contains large amounts of nitrate (KNO3). After incubation, reagent added simultaneously reacts with nitrite and turn to red color, indicating a positive nitrate reduction. If there is no color change at this step, nitrite is absent. If the nitrate is unreduced and till in its original form, this would be a negative nitrate reduction result. However it is possible that the nitrate was reduced to nitrite but has been further reduced to ammonia or nitrogen gas. This would be recorded as positive nitrate reduction result. Under anaerobic conditions, some bacteria are able to use nitrate (NO3-) as an external terminal electron acceptor. This kind of metabolism is analogous to the use of oxygen as a terminal electron acceptor by aerobic organisms and is called anaerobic respiration. Nitrate is an oxidized compound and there are several steps possible in its reduction. The initial step is the reduction of nitrate (NO3-) to nitrite (NO2-). Several possible products can be made from further reduction of nitrite. Possible reduced end products include the following N2, NH3 (ammonia), N2O (nitrous oxide). Bacteria vary in their ability to perform these reactions, a useful characteristic for identification. A medium that will support growth must be used and the cells must be grown anaerobically. Growth in the presence of oxygen will decrease or eliminate nitrate reduction. There are many possible end products of nitrate reduction such as nitrite, nitrogen gas (N2), nitrous oxides, ammonia, and hydroxylamine. The disappearance of nitrate or the appearance of the end products. The test relies on the production of nitrous acid from the nitrite. This, in turn, reacts with the iodide in the reagent to produce iodine. The iodine then reacts with the starch in the reagent to produce a blue color. Since some of the possible products of NO3- reduction are gaseous, a Durham tube is sometimes inverted in the culture tube to trap gases. This being the case, it is important to pre-test the medium to ensure no detectable nitrite is present at the beginning, and, in the case of a negative test, to reduce any nitrate to nitrite to determine whether the nitrite was also reduced. If nitrite is produced, it reacts with hemoglobin to give a bright red color, instead of the dark red color of hemoglobin. It is this reaction that is responsible for the color of meats, such as hot dogs, which are preserved with sodium nitrite. The blood agar test has the advantage of no color change occurring if the nitrite is further reduced. F. UREASE TEST Urease test mainly highlighted to determine the ability of the organism to split urea forming 2 molecules of ammonia by the action of the enzyme Urease with resulting alkalinity. Negative reaction shown by E. coli meanwhile Klebsiella spp. shows positive result. Extra precaution needed because both the urease test medium depend upon the demonstration of alkalinity that not specific for urease. Moreover the protein hydrolysis may result I alkalinity hence false positive may be seen in Pseudomonas. The false positivity can be eliminated by control test using the same medium without urea as recommendation. Urea is a nitrogenous waste product of animals. Some bacteria can cleaved it to produce carbon dioxide and ammonia. The ammonia is a nitrogen source for amino acid biosynthesis as well as for synthesis of other nitrogen-containing molecules in the cell. The urease test was devised to distinguish Proteus species from other enterics. The medium described here is buffered enough so that weak urease producers appear negative. The production of ammonia raises the pH of the medium. The indicator phenol red is present in the broth. Phenol red is orange-yellow at pH below than 6. 8, and turns bright pinkish-red at pH higher than 8. 1. Hence, a positive urea test is denoted by the change of medium color from yellow to pinkish red. CONCLUSION: Based on the laboratory, different bacteria species have different abilities to metabolize various substrates and end products formed were able to be observed and distinguished. Biochemical Action of Bacteria To observe the growth of different bacteria species in term of structures and its morphology based on different chemical substance applied. 3. To observe physiological and immunological properties utilized by different species of bacteria. INTRODUCTION: Bacteria biochemical testing can determine the types and numbers in terms of colony forming units of bacteria present in a sample of different chemical. The testing could be focused on a specific type of bacteria, medical bacteria or a broad range of environmental bacteria. Since bacteria are present in virtually any environment, it’s important to be clear why the testing is being performed. The more specific the testing is the better and the easier it is to interpret the results. Numbers and types of bacteria that should be a cause for concern depends upon several factors, including the type of bacteria present and the type of samples. Escherichia coli  are one of the main species of bacteria living in the lower intestines of mammals. E. coli  can be found in the intestinal tract of warm-blooded animals. The presence of  E. coli  in foods is considered to be an indication of fecal contamination. Staphylococcus  organisms are commonly found in the environment. Several species of  Staphylococcus  are found on the skin, intestines, nasal passages, etc. of warm-blooded animals. Some species of  Staphylococcus, particularly  Staphylococcus aureus  can be pathogenic are capable of causing illness. Pseudomonas aeruginosa is widely distributed in soil, water and plants. It survives in hot tubs, whirlpools, contact lens solution, sinks and showers. It can cause a number of opportunistic infections including infections of the skin, external ear canal and of the eye. Nitrifying bacteria recycle organic nitrogenous materials from ammonium (the endpoint for the decomposition of proteins) to nitrates. Their presence can indicate that the water may have been polluted by nitrogen-rich organics from sources such as compromised septic tanks, sewage systems, industrial and hazardous waste sites and is undergoing an aerobic form of degradation. The presence of denitrifying bacteria can indicate that the water has been polluted by nitrogen-rich organics from sources such as compromised septic tanks, sewage systems, industrial and hazardous waste sites. MATERIALS: 1. Nutrient broth cultures of Escherichia coli . Nutrient broth cultures of Serratia marcescens 3. Nutrient broth cultures of Salmonella typhimurium 4. Nutrient broth cultures of Bacillus subtilis 5. Nutrient broth cultures of Klebsiella spp. 6. Nutrient broth cultures of Streptococcus spp. 7. Nutrient broth cultures of Staphylococcus aurieus 8. Nutrient broth cultures of Proteus vulgaris 9. Nutri ent broth cultures of Pseudomonas fluorescens 10. Parafilm tape 11. Inoculating loops 12. Gloves 13. Incubator 14. Nutrient agar plate 15. Nutrient agar slants 16. Starch agar plates 17. Gelatine agar plates 18. 2 tubes Clark’s-Lub medium (MR-VP medium) 19. Tryptone broth 20. 3 Kigler’ slant 21. 5 tubes nitrate broth ( 0. 1% KNO3) 22. 5 urea broth 23. Tube containing 10ml of sterile saline 24. Glucose broths with Durham tubes and phenol red indicator 25. Lactose broths with Durham tubes and phenol red indicator 26. Sucrose broths with Durham tubes and phenol red indicator 27. Gram’s iodine 28. Kovac’s indol reagent 29. Mercuric chloride solution 30. KOH-creatine solution or 40% KOH 31. FR reagent 32. Nessler’s reagent PROCEDURE: A. CARBOHYDRATE METABOLISM 1. Fermentation of sugars Materials: 1. Glucose broths with Durham tubes and phenol red indicator 2. Lactose broths with Durham tubes and phenol red indicator 3. Sucrose broths with Durham tubes and phenol red indicator 4. 18 hour nutrient broth cultures of E. coli and S. typhimurium Procedure: 1) The small bottles of different sugars were inoculated with a loopfuls of E. coli and Salmonella spp. 2) The tubes were labelled and incubate at 37oC for 24 hours 3) All observations were recorded for presence of acid or gas production. 2. Hydrolysis of starch Materials: 1. Starch agar plates 2. Broth agar cultures of B. subtilis and E. coli Procedure: 1) Starch plate was streaked with E. coli in for sections and repeated for B. ubtilis bacteria in other starch plate. 2) The plates were secured with parafilm, labelled and inoculated at 37oC for 24 hours. The following day 1) The plates were tested for starch hydrolysis by flooding the pates with Gram’s iodine. 2) The plates were examined and the colonies that showed clear uncoloured zones in contrast with the blue-black background of the starch-iodine complex were noted. 3) The extent of the zones of hydrolysis indicated either the reddish colour zones were seen. 4) All results and observations were recorded. B. PROTEIN AND AMINO ACID METABOLIM 1. Indole test Materials: 1. Broth cultures of B. ubtilis, E. coli, and S. typhimurium 2. 3 tubes of tryptone broth 3. Kovac’s indole test reagent Procedures: 1) The peptone water was inoculated with a loopfuls of the test organism. 2) The tube was labelled and incubated for 24 hours. The following day 1) The tubes were added with a few drops of Kovac’s indole reagent (dimethylaminobenzaldehyde) 2) The red or dark color indicates the presence of indole. 4. Hydrogen sulphide Materials: 1. Broth cultures of B. subtilis, E. coli, and S. typhimurium 2. 3 Kigler’s slant Procedures: 1) The Kigler’s slant was inoculated with a loopfuls of the test organism by the stab method. ) The tube was labelled and incubated for 24 hours. The following day 3) Th e Kigler’ slant was observed for production of H2S where the black precipitate along the line of growth in the Kigler’s slants indicated the H2S have been produced. 4) The observations were recorded. 3. Gelatine hydrolysis test Materials: 1. Broth cultures of B. subtilis, E. coli, and S. typhimurium 2. Gelatine agar plates 3. Mercuric chloride solution Procedures: 3) The gelatine agar plates were inoculated with a loopfuls of the test organism with a single streak at the centre of the plates. ) The plates were secured with parafilm, labelled and incubated for 24 hours. The following day 5) The plates were flooded with mercuric chloride solution. 6) The medium become opaque in regions that still contain gelatine and clear regions where gelatine has been hydrolysed. C. VOGES-PROSKAUER TEST Materials: 1. Broth cultures of E. coli, and Klebsiella spp. 2. 2 tubes of Clark-Lub’s medium (MR-VP medium) 3. KOH-creatine solution Procedures: 1) The tubes of Clark-Lubâ€⠄¢s medium (MR-VP medium) were inoculated with a loopfuls of the test organism. 2) The tubes were labelled and incubated for 24 hours. The following day 1) The tubes were tested with Voges-Proskauer test. 2) The 0. 5ml of KOH-creatine solutuin was addd. 3) The tube was shaked vigorously for 30 seconds. 4) The red or pink color indicates the presence of acetoin. D. CATALASE TEST Materials: 1. Broth cultures of Streptococcus spp. and Staphylococcus aureus. 2. Nutrient agar slant Procedures: 1) The nutrient agar slant was inoculated with a loopfuls of the test organism. 2) The tube was labelled and incubated for 24 hours. The following day 1) The tubes were tested with catalase test by adding several drops of a 5% solution of hydrogen peroxide. ) The vigorous bubbling indicates the presence of oxygen. E. NITRATE REDUCTION TEST Materials: 1. Broth cultures of E. coli, Proteus vugaris, Serratia marcescens, Pseudomonas fluorescens. 2. 5 tubes containing nitrate broth (0. 1% KNO3) 3. Nitrate test reagent Procedures: 1) The nitrate broth was inoculated with a loopfuls of the test organism. 2) The tube was labelled and incub ated for 24 hours. The following day 1) The tubes were tested with 1ml of Follet and Ratcliff’s (FR reagent) 2) The orange or brown color indicates the presence of nitrate. 3) The absent of nitrate indicates that: a. There has been no nitrate reduction b. The reduction has proceeded beyond that nitrate stage. 4) The absent of orange or brown color were further tested with small amount of cadmium to the tube. If nitrate still present, it will be catalytically change to nitrate which will then reacts with the FR reagent in the tube. 5) In the absent of a positive nitrate result, the bubbles f H2 gas was observed in the Durhams tube OR 6) The samples were tested with 1ml of Nessler’s reagent. The brown or orange color indicates the presence of ammonia. F. UREASE TEST Materials: 1. Broth cultures of E. coli, P. vugaris, S. arcescens, P. fluorescens. 2. 5 urea broth with indicator Procedures: 1) The urea broth was inoculated with a loopfuls of the test organism. 2) The tube was labelled and incubated for 24 hours. The following day 1) The urease-positive organism produced in intense red/purple coloration of the medium after incubation. 2) All observations were recorded. RESULTS AND OBSERVATION: Test| Observation(After 24 hours incubation)| Description| A. Carbohydrate Test 1. Fermentation of starchDurham tubes and phenol-red indicator. 2. Hydrolysis of starch| Glucose: Lactose: Sucrose: Starch agar plates:B. ubtilisE. coli| * Positive result for E. coli as tube turn yellow * Positive result for S. typhimium as tube turn yellow * Positive result for E. coli as tube turn yellow * No gas produced by S. typhimium because the tube turns red. * No gas produced by E. coli because the tube is slightly red. * Positive result for S. typhimium as tube turn yellow * Positive zone of clearing. * Negative zone of clearing. | B. Protein And Amino Acid Metabolism 1. Indole test 2. Hydrogen disulphide 3. Gelatine hydrolysis test| Tryptone broth:B. subtilisE. coli. S. typhimuriumKigler’s slant:B. subtilisE. oli. S. typhimuriumGelatine agar plates:B. subtilisE. coli. S. typhimurium| * Negative Indole tests no color change. * Bright fuschia at the interface is positive test for Indole . * Negative Indole tests no color change. * Black precipitate form shows positive sulphur reduction. * Negative reaction. * Positive reaction forming the black precipitate. * Positive hydrolysis of gelatine into amino acid to be used as nutrients/gelatinase. * Negative hydrolysis of gelatine. * Negative hydrolysis of gelatine| C. Voges- Proskaeur’s Test| MR-VP medium:E. coli. Klebsiella spp. | * Negative results of E. oli * Positive results Klebsiella spp. | D. Catalase Test| Nutrient agar slant:S. aureusStreptococcus spp. | S. aureus * Positive catalase reaction because present of bubblesStreptococcus spp. * Negative catalase reaction no bubbles present. | E. Nitrate Reduction Test| Nitrate broth:E. coliP. vulgarisS. marcescensP. fluorenscens| * No color change after denitrification of ammonia. * No color change after denitrification of ammonia. * Turns red. Positive nitrate test shows nitrate reductase present. * Turns red but negative catalase test. | F. Urease Test| Urea broth:E. coliP. vulgarisS. marcescensP. luorenscens| * Negative urease test because the tube remain purple. * P. vulgaris show positive urease test from yellow to pinkish. * S. marcescens show negative urease test because the color remain purple. * P. fluorenscens show negative urease test because the color remain purple. | DISCUSSION: Biochemical tests of bacteria oobjectively to test the metabolism of carbohydrate and related products of different bacteria species, test specific breakdown of products through color changes and gas produced. Besides that, the ability of bacteria utilizes a specific substance and the metabolism of protein and amino acid by bacteria. A. CARBOHYDRATE TEST Carbohydrate is an organic compound that consists of only carbon, hydrogen and oxygen which is basically the major carbon source of most organisms. Specific carbohydrate can be fermented by organism that incorporated in a medium producing red or acid with gas. Pinkish red color shows positive results where acidic content formed in the tube because carbon dioxide realised if fermentation occur. Negative catabolism of carbohydrate shows by yellow to colourless of Durham’s tube as the solution remain alkaline in the absent of carbon dioxide gas. Gas production can be seen as bubbles in Durham’s tube. Central carbohydrate metabolism or the breakdown of sugars into smaller compounds accompanied by the production of ATP and reduction of coenzymes, follows one of several pathway. Carbohydrate utilization and fermentation will be assessed by growing cells without shaking (aeration) in defined media containing a single carbohydrate. Acid products of sugar fermentation will cause a noticeable color change in the pH indicator included in the medium. Sugar fermentation does not produce alkaline product, however non-fermentative hydrolysis of amino acids in the peptone, present in most fermentation media, may give an alkaline reaction, which will also cause a color change in the pH indicator. Gas production, H2 in particular, can be determined by placing a small, inverted Durham tube in the test medium. If gas is produced, it is trapped in the Durham tube and can be seen as a bubble. Hydrogen sulfide (H2S) is produced by bacterial anaerobic degradation of the two sulfur-containing amino acids, cysteine and methionine. Hydrogen sulfide is released as a by-product when carbon and nitrogen atoms in the amino acids are consumed as nutrients by the cells. Under anaerobic conditions the sulfhydryl (-SH) group on cysteine is reduced by cysteine desulfurase. Ferrous ammonium sulfate-indicator. H2S reacts with ferrous sulfate forming the black precipitate Sodium thiosulfate is reduced to sulphite/thiosulfate The Kligler’s Iron test is used to detect liberation of H2S gas by bacteria growing on an excess of these sulfur-containing amino acids. The agar contains high levels of peptones or sources of cysteine and methionine and ferrous sulfate as an indicator. When H2S is produced, the ferrous ion reacts with it to give ferrous sulfide, an insoluble black precipitate. In starch hydrolysis test Iodine must be on the plate to visualize the zone of clearing surrounding the bacteria. This zone indicates starch was broken down to dextrins, maltose, and glucose. B. PROTEIN AND AMINO ACID METABOLIM Indole test measures the ability of bacteria to split indole from tryptophan molecule but in term of biochemistry, Indole test is one of the metabolic degradation products of the amino acid tryophan. Bacteria that possess the enzyme trytophanase are capable of hydrolysing and deaminating tryptophan with the production of Indole, pyruvic acid and ammonia. Positive reaction showed by E. coli, P. vulgaris and negative results observed in Klebsiella and Salmonella from observation in the Indole test. Development of fuchsia red color at the interface of the reagent and the broth within seconds after adding the reagent is indicative of the presence of Indole and is a positive test. Kovac’s reagent detects if tryptophan has been hydrolyzed to indol or tryptophanase. Gelatin is the protein derived from the animal protein collagen, has been used as a solidifying agent in food for a long time besides nutrient gelatine as an early type of solid growth medium. One problem is that many bacteria have the ability to hydrolyze or liquefy the gelatin. This gelatin liquefaction ability forms the basis for this test. C. VOGES-PROSKAUER TEST The production of acetoin by bacteria is perform through Voges Proskauer Test to determine the ability of the organisms to produce neutral end product acetyl methyl carbinol (acetoin) from glucose fermentation. Negative results gained from E. coli meanwhile positive reaction gives by. Changing of color to red pinkish color at the surface of the medium indicated positive results and yellow color at the surface of the medium show negative reaction. The KOH reagent should not be excessively added to the sample because excess KOH may mask weak VP positive reactions. The MR test will be positive for organisms that have complete pathways for mixed acid fermentation. The Voges-Proskauer (VP) test determines whether a specific neutral metabolic intermediate, acetoin, has been produced instead of acid from glucose. Acetoin is the last intermediate in the butanediol pathway, which is a common fermentation pathway in B. subtilis. The tests are complementary in the sense that often a bacterium will give a positive reaction for one test and a negative reaction for the other. The three possible patterns of results where the acetoin fermentation pathway, detected by the VP test, two molecules of pyruvate condense and two molecules of CO2 are released. The 4 carbon intermediate that is formed, acetoin, contains a carbonyl group. The acetoin acts as a terminal electron acceptor with the carbonyl group being reduced to a hydroxyl group. The reduced product, butanediol, is excreted by the bacteria and acetoin is oxidized to diacetyl by alkaline -naphthol, which forms a red complex with creatinine. D. CATALASE TEST Catalase is present in most cytochrome containing aerobic and facultative anaerobic bacteria except Streptococcus spp. Hydrogen peroxide forms as one of the oxidative end product of aerobic carbohydrate metabolism. If hydrogen peroxide allowed accumulating in the bacterial cells it becomes lethal to the bacteria. Catalases help in converting H2O2 to water and oxygen. In the catalase test performed, Streptococcus spp gives negative reaction as for S. aureus, the positive reaction occurred. One of the by-products of oxidation-reduction in the presence of O2 during aerobic respiration is hydrogen peroxide (H2O2). This compound is highly reactive and must be degraded in the cytoplasm of the cell producing it. It can be especially damaging to molecules of DNA. Most aerobes synthesize the enzyme catalase, which breaks down H2O2 into water and oxygen. The O2 gas is identified by the production of bubbles from a concentrated cell suspension. The test for catalase is simple and usually very reliable. It is a major method of distinguishing between Staphylococcus (catalase positive), Streptococcus (catalase negative), and Enterococcus (catalase negative), although some strains of Enterococcus faecalis may be positive. Catalase production is generally associated with aerobic organisms, since H2O2 is a toxic by-product of aerobic growth, but not always. E. NITRATE REDUCTION TEST Nitrate reduction test basically test the ability of organism to reduce the nitrate to nitrites of free nitrogen gas. In order to determine either the bacteria can reduce nitrate, the test organism is inoculated into nitrate reduction broth, undefined medium that contains large amounts of nitrate (KNO3). After incubation, reagent added simultaneously reacts with nitrite and turn to red color, indicating a positive nitrate reduction. If there is no color change at this step, nitrite is absent. If the nitrate is unreduced and till in its original form, this would be a negative nitrate reduction result. However it is possible that the nitrate was reduced to nitrite but has been further reduced to ammonia or nitrogen gas. This would be recorded as positive nitrate reduction result. Under anaerobic conditions, some bacteria are able to use nitrate (NO3-) as an external terminal electron acceptor. This kind of metabolism is analogous to the use of oxygen as a terminal electron acceptor by aerobic organisms and is called anaerobic respiration. Nitrate is an oxidized compound and there are several steps possible in its reduction. The initial step is the reduction of nitrate (NO3-) to nitrite (NO2-). Several possible products can be made from further reduction of nitrite. Possible reduced end products include the following N2, NH3 (ammonia), N2O (nitrous oxide). Bacteria vary in their ability to perform these reactions, a useful characteristic for identification. A medium that will support growth must be used and the cells must be grown anaerobically. Growth in the presence of oxygen will decrease or eliminate nitrate reduction. There are many possible end products of nitrate reduction such as nitrite, nitrogen gas (N2), nitrous oxides, ammonia, and hydroxylamine. The disappearance of nitrate or the appearance of the end products. The test relies on the production of nitrous acid from the nitrite. This, in turn, reacts with the iodide in the reagent to produce iodine. The iodine then reacts with the starch in the reagent to produce a blue color. Since some of the possible products of NO3- reduction are gaseous, a Durham tube is sometimes inverted in the culture tube to trap gases. This being the case, it is important to pre-test the medium to ensure no detectable nitrite is present at the beginning, and, in the case of a negative test, to reduce any nitrate to nitrite to determine whether the nitrite was also reduced. If nitrite is produced, it reacts with hemoglobin to give a bright red color, instead of the dark red color of hemoglobin. It is this reaction that is responsible for the color of meats, such as hot dogs, which are preserved with sodium nitrite. The blood agar test has the advantage of no color change occurring if the nitrite is further reduced. F. UREASE TEST Urease test mainly highlighted to determine the ability of the organism to split urea forming 2 molecules of ammonia by the action of the enzyme Urease with resulting alkalinity. Negative reaction shown by E. coli meanwhile Klebsiella spp. shows positive result. Extra precaution needed because both the urease test medium depend upon the demonstration of alkalinity that not specific for urease. Moreover the protein hydrolysis may result I alkalinity hence false positive may be seen in Pseudomonas. The false positivity can be eliminated by control test using the same medium without urea as recommendation. Urea is a nitrogenous waste product of animals. Some bacteria can cleaved it to produce carbon dioxide and ammonia. The ammonia is a nitrogen source for amino acid biosynthesis as well as for synthesis of other nitrogen-containing molecules in the cell. The urease test was devised to distinguish Proteus species from other enterics. The medium described here is buffered enough so that weak urease producers appear negative. The production of ammonia raises the pH of the medium. The indicator phenol red is present in the broth. Phenol red is orange-yellow at pH below than 6. 8, and turns bright pinkish-red at pH higher than 8. 1. Hence, a positive urea test is denoted by the change of medium color from yellow to pinkish red. CONCLUSION: Based on the laboratory, different bacteria species have different abilities to metabolize various substrates and end products formed were able to be observed and distinguished.

Write summery about what these websites are about Annotated Bibliography

Write summery about what these websites are about - Annotated Bibliography Example and Northern Development Canada that was first called Indian and Northern Affairs Canada (INAC) is discriminating in fairly providing funds for children of aboriginal reserves. They also claim that the children are also being denied to welfare benefits of reserves. . It is not only about the indigenous children who are suffering at the hands of government but there are other issues like water crisis and more than 582 indigenous women murdered and missing but no action has been taken so far by the Canadian government. That’s why, the society has sued against the INAC for showing this acute prejudice. The plea has been filed to Canadian Human rights commission alleging that the federal government has differentiated between the children of first nations and those originally from Canada on racial basis. Â  The society and INAC worked for several years to eliminate inequality but all efforts by society went to vain as the federal government did not show any response to efforts done so far but failed badly to develop solutions to redress inequalities among children on racial basis. Canadian Human Rights Commission found in 1977, is an autonomous government body that deals with the Canadian Human Rights Act. The Canadian commission has the right to investigate complaints filed on racial and discriminatory basis under federal jurisdiction and also has jurisprudence to hear the cases filed in favour of children on reserves of first nations. The society has also filed another plea to the commission in 2010, accusing that the Aboriginal and INAC are not only prejudiced against the children of first nations but they have racist attitudes against the FNCFC society too as they excluded the society’s executive director, Cindy Blackstock from the meetings aimed at development of first nations. The society has accused that the handling of society’s members by INAC has been ridiculous so far and was based on retaliation. The commission later on directed the case to the

Taxation Assignment Example | Topics and Well Written Essays - 1750 words - 5

Taxation - Assignment Example Finney (2004) observed that governments make use of taxation to discourage or encourage economic decisions. For example, the government could reduce taxes on personal income by the money paid as interest on mortgage loans, hence resulting in more construction activities that generate more employment. Taxation in the UK mainly involves making payments to the local and central government. The local government revenues are received in form of grants from the central government finances and fees from street parking while the central government receives revenues from income tax, value added tax, fuel duty, National Insurance contributions, and corporation tax (Viitala, 2005). This document is going to give opinions on whether the UK government should restore the 50% additional rate of income tax or not. The document will provide a brief explanation on the recent history of the additional rate of the income tax and then discuss arguments in favour of and against the 50% additional rate of income tax. The 50% additional income tax rate was introduced in April 2010 by the then Chancellor, Alistair Darling (Ault and Arnold, 2010). The 50% rate applied to those individuals who had incomes of above 150,000 pounds. Initially in Chancellor Darling’s budget in 2009, he had announced that various tax increases would add up to more than 6 billion pounds by 2012, in order to safeguard the economic future and to assist the citizens when in need. The changes in the budget included an increase in the rates of indirect taxes especially duties on highway fuel and alcohol for that tax year, and changes in income tax from April 2010 that included the new 50% rate on all incomes above 150,000 pounds. The increases in tax rates, especially the new 50% rate, initiated reactions to the budget as many viewed it as a major change in the government’s labour approach to charging those who are wealthy (King, 2011). King (2011) noted that the HM