out of 4 given samples A‚ B‚ C and D. Research Question: Out of the four given samples which sample consists of protein/ starch/reducing sugar/ disaccharide? What color changes will help to identify the contents of each sample when treated with iodine‚ biuret agent and benedicts solution? Theory and background information: What is a protein?1 Proteins are macromolecules‚ consisting of one or more chains of amino acid residues. Proteins perform a vast array of functions within living organisms
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(2013‚ February 21). Amylase. Retrieved February 27‚ 2013‚ from Wikipedia: http://en.wikipedia.org/wiki/Amylase Introduction: Aim: is to find out what the pH level of Amylase is. Variables: Controlled variables: are amount of amylase‚ starch‚ iodine‚ buffer solution and time. Independent variables: are the different buffer solutions being used. Dependant variables: are the different pH levels being registered. Hypothesis: My hypothesis is that the Amylase will register at around a
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) Ascorbic acid‚ C6H8O6‚ is a reducing agent that reacts rapidly with iodine (I2) in acidic medium to produce iodide ion (I-) and dehydroascorbic acid‚ as shown in the following equation: [IMAGE] + I2(aq) -----------> + 2H+(aq) + 2I-(aq) Ascorbic acid (Vit. C) Dehydroascorbic acid However‚ since iodine is only slightly soluble in water‚ ascorgic acid should not be titrated directly by a standard iodine solution‚ since the end point of titration is not o obvious. Instead‚
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positive metal ions in the solutions are less powerful reducing agents‚ then the metal in the plate will be reduced and hence form a deposition of solid metal. e.g. Zn + Pb2+-> Zn2+ + Pb EXPERIMENT 2: Aim: To range the halogens bromine‚ chlorine and iodine‚ with the strongest oxidising agent first. Hypothesis: A strong oxidising agent is a species that easily gains electrons‚ and is hence easily reduced. The ionisation energy of the halogens (Cl2‚ I2‚ Br2) decreases down the group‚ which means that
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Biuret Test for amino groups present in proteins. The Iodine Test to identify the presence of starch. The Grease Spot Test and the Sudan Dye test to identify the presence of lipids (fatty acids). The Benedict’s Test to identify the presence of reducing sugars. In the biuret test if the test result for protein changes a color of lavender‚ purple or pink‚ the test result for protein is positive using the Biuret reagent. In the iodine test If the Iodine turns black or blue-black there is starch present
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focused on finding the ratio of reactants to products to be either 1 to 1 or 1 to 2. In our case the reactants was Lead (II) Nitrate and Potassium Iodine. These two when mixed together make Lead Iodide and Potassium Nitrate. We also had to try and find if the number of moles of Lead(II) Nitrate was the same as the final number of moles for Lead Iodine after the experiment. Our data for the lab had pinpoint accuracy. Proved by the data table below Trials Volume of Pb(NO3)2 Mol Pb(NO3)2 Mol KI Mass
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study the structure of cells under different magnifications. To differentiate between the structure of plant cells and animal cells. To learn the steps and techniques to use a microscope. Materials: Potato‚ onion‚ cheek cell‚ distilled water‚ iodine solution‚ filter paper‚ toothpick and methylene blue solution. Apparatus: Knife‚ light microscope‚ glass slide‚ cover slip‚ forceps‚ mounting needle‚ dropper and white tile.Methods: I) Observation of starch grains The potato was cut to obtain
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negative result because biuret reagent is blue to begin with. If a solution is pinkish purple‚ or purple‚ then the test for protein is positive. The test solution for starches is yellowish brown. If any substance that is yellowish brown when mixed with iodine‚ then the test for starches is negative. If the solution turns purple‚ or a dark purplish black‚ then the test for starches is positive. If DI water‚ and sucrose are tested for proteins using biuret reagent‚ then they will show a negative result
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used are ethanol (60–90%)‚ 1-propanol (60–70%) and 2-propanol/isopropanol (70–80%) or mixtures of these alcohols. They are commonly referred to as "surgical alcohol". Used to disinfect the skin before injections are given‚ often along with iodine (tincture of iodine) or some cationic surfactants (benzalkonium chloride 0.05–0.5%‚ chlorhexidine 0.2–4.0% or octenidine dihydrochloride 0.1–2.0%). Quaternary ammonium compounds Also known as Quats or QAC’s‚ include the chemicals benzalkonium chloride (BAC)
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due to iodine deficiency and cases are more common in developing countries due to the lack of iodine in diets. Iodine is extremely important in thyroid function because it is used in thyroid hormone production. Goiters are more closely associated with Hashimoto’s disease since TSH stimulation causes the thyroid to grow. In some cases‚ goiters can be associated with hyperthyroidism‚ such as Grave’s Disease depending on thyroid hormone levels (American Thyroid Association). Aside from iodine deficiency
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