Sucrose is found in table sugar, and is often formed as a result of photosynthesis sunlight absorbed by chlorophyll reacting with other compounds in plants. They are generally established in refined sugar such as white glucose. Colonies of Proteus inhabits the intestinal tracts of humans and animals. Through the use of indicators we determined the presence or absence of organic compounds. Because of the density of oil and water, the oil continues to float on top of the water without mixing. Materials 1 9 tubes 2 Iodine 3 Clinitest tablets 4 Starch 5 Glucose 6. Objective: To characterize carbohydrates present in an unknown solution on the basis of various chemical assays.
Group Building Block Large Molecule Function To Identify, Look for. It looked over grown, so the same nutrient agar test was carried out several times. Physical constants such as melting points have traditionally been used by organic chemistry for identification of unknown compounds. It was recommended that I start a blog about my education experiences and about my intended major Geology. The citrate test showed a negative result with no color change or growth of the unknown bacterium. Then, we got a beaker, filled it halfway with water, and placed it on the hot plate. Thus it will not show any changes compare to the carbohydrates.
Lipids are made of carbon, hydrogen, and oxygen. This can be achieved by studying their chemical properties and structure. Motility is determined by simply examining if there is any radiating growth from a stab line after stab inoculating the bacteria with an inoculating needle. The carbohydrate test for starch was self-explanatory. Carbohydrate Lab Report Introduction Qualitative identification of a substance is of significant importance in chemistry. The distilled water served as a control for the experiment.
The gram positive bacteria was inoculated into a mannitol fermentation tube and placed into the incubator. Within this test, all kind of carbohydrates gives a positive effect. Lipids are non-polar and they are insoluble in water or other polar liquids. The test solutions containing Molisch reagent is discarded into the container provided by laboratory instructor. In unknown 1, sugar was the only substance that was present. In starch, all the glucose repeat units are oriented in the same direction.
The monomers are reducing sugars which gave the positive result on the second reducing sugar test. Monosaccharides give a rapid positive test. Both organic compound contribute to our lives, and our health is heavily dependent on them. For the Biuret Test, the colour change occurs when there is protein inside the solution. The immediate formation of a vivid blue color indicates amylose. Each test tube was filled with at least 2-3 mL of one solution.
Staphylococcus epidermidis is resistant to most antibiotics like methicillin, novobiocic, and benzyl penicillin, but it is antibiotic sensitive to vancomycin. Conclusion Each test which was conducted in this lab confirmed the hypothesis and provided insight into how negative and positive controls are conducted in a laboratory setting. Within the urea broth all of the essential nutrients that bacteria would need are provided by peptone and glucose and the potassium phosphate is used as a mild buffer that resists alkalinization due to peptone metabolism. A gram stain was taken from a sample of the bacteria growing on the nutrient agar. Carbohydrate chemistry allows us a great opportunity to better understand qualitative testing.
Five drops of copper sulfate solution was added to each tube and swirled to mix. After five drops of the methyl red reagent were added a red color began to form which was an immediate indication of a positive test. The Casein test concluded negative for the bacterium having casease to hydrolyze casein. Lastly, an Oxidase test showed positive for the bacterium having cytochrome c. We uses these reagents to test an unknown for specific nutrients.
Through this test, one is able to determine that the unknown solution 128 is a non-reducing sugar because the results show that the test turned out positive, and reducing sugars cause negative tests to occur. This test is specific for monosaccharides. Since the unknown bacteria was a gram negative rod, a gelatin test was performed and the organism was inoculated into a gelatin agar tube and placed into the incubator. One of the main types of nutrients is the carbohydrates. Discussion This experiment required many different biochemical tests to be conducted for a few reasons; the first being to identify which bacteria was the one that was randomly selected and secondly for educational purposes so that students will become familiar and gain experience about the different types of media and laboratory techniques. Some plants store food as sugar, while others store it as starch. Verifying the gram negative bacteria is Escherichia coli.
Two categories of amylases, denoted alpha and beta, differ in the way they attack the bonds of the starch molecules. A drop of iodine was added. The citrate test truly helped confirm that the unknown bacteria 25 was in fact Escherichia coli. In my lab report for the Density Lab I recorded the steps to the lab. Apple and cabbage contain carbohydrate so that they gave purple ring in this test. Methemoglobin is not a problem in adults since they have an enzyme that converts methemoglobin back to hemoglobin. The actual broth is made with urea, peptone, potassium phosphate, glucose, and phenol red.
Physical constants such as melting points have traditionally been used by organic chemistry for identification of unknown compounds. Pentoses yield furfural while Hexoses yield 5-Hydroxy methyl furfurals. The results are compared with those obtained without acid treatment. Albumin turned out to contain protein by testing it with Biuret Reagent. Conclusion The exercises for carbohydrates mostly resulted in the former hypothesis.