...Color Reactions of Protein Casein Abstract In this experiment different kinds of processes were done to isolate the different kinds of proteins. The protein casein was extracted from skimmed milk through isoelectric precipitation, albumin was also extracted from skimmed milk through heat denaturation, gluten was isolated from wheat flour through difference in solubility, and myoglobin from beef meat through salting out or salt-induced precipitation. The main objective of the qualitative color reaction of the proteins is to analyze the chemical groups present in the protein and explain the principle involved in each test. Biuret Test, Ninhydrin Test, Xanthoproteic Test, Millon’s Test, Hopkins-Cole Test, Sakaguchi Test, Nitroprusside Test, Fohl’s Test, Test for Amides, and Pauly Test were the different tests that were performed. Each test corresponds to the different reagents that were used. In the different tests performed, positive and negative results are gathered that indicates the presence or absence of a particular amino acid in the protein. Introduction Proteins are probably the most important class of biochemical molecules, although of course lipids and carbohydrates are also essential for life. Proteins are the basis for the major structural components of animal and human tissue. Proteins are natural polymer molecules consisting of amino acid units. The number of amino acids in proteins may range from two to several thousand.[3]Biologically active proteins...
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...molecules of cells include proteins, carbohydrates, and lipids, which are composed of smaller molecules known as monomers and polymers. Polymers are joined monomers. A chemical reaction links monomers together occurs and releases a water molecule, this is called dehydration synthesis. Hydrolysis separates polymers into monomers by using water to break bonds. Organic catalysts called enzymes are proteins that increase the speed of a chemical reaction. In the lab we used Biuret reagent to test for proteins, iodine solution to test for starch, paper to test for lipids. In the first lab, we tested for the presence of proteins in samples by using blue solution called Biuret reagent, which changes to purple when a protein is present and pinkish-purple for peptides. First test tubes were marked at 1cm and then filled to the mark with water, albumin, pepsin, and starch. Next, five drops of Biuret reagent was added to the sample, covered with Parafilm, and swirled to mix. The water remained clear, indicating the sample lacked the presence of proteins, and thus was our negative control. The albumin sample observed changed to an orange-purple color, indicating the presence of protein. The peptin sample changed to a pink-purple hue, testing positive for presence of peptides. The starch sample test tube turned opaque, indicating starch is not a protein. The results of the experiment were in line with my predictions. Although I knew that starch and water would lack protein I was unsure about...
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...Determination of presence of protein in a variety of food substances by the use of Biuret Reagent Biol. 1040 Section 1005 Introduction The human body consumes carbohydrates, lipids, and proteins each day by eating a variety of foods. These foods are required for energy and human growth. Proteins are a diverse group of macromolecules with many different functions (Mbuthia, 2012). Many are structural components of bone, muscle, hair, tissue, etc. Others are enzymes that speed up cellular reactions. All proteins are made up of amino acids (Johnson, 2010). The purpose of this experiment is to determine whether peptide bonds are present in various food substances. The color violet will indicate the presence of proteins. The more intense the color is, the greater number of peptide bonds there are (Mbuthia, 2012). Methods Using the China marker, I numbered test tubes 1-5 for identification purposes. Using a pipet I added 1 milliliter of each solution to it’s designated test tube. Next, I added 5 drops of the Biuret reagent to each test tube and agitated the mixture by shaking the tubes from side to side. After waiting 2 minutes I recorded the color of each mixture. I used the color reaction after adding the reagent to determine the presence of proteins in each substance (Mbuthia, 2012). Results Test solutions that contained proteins reacted to the Biuret reagent by turning violet. Table 1 summarizes the test results. In summary, test solutions, including distilled...
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...Enzyme Concentration , and Substrate Concentration on Catecholase Introduction Enzymes are biological proteins that speed up the reaction rate of a chemical reaction. They work in the human body by lowering activation energy making certain that reactions will initiate. For every action, there is an equal and opposite reaction. In this case, factors that influence the activity of an enzyme are called modulators. If modulators activate enzymes the reaction rate catalyzed will significantly increase, but if the modulator inactivates enzymes the reaction rate catalyzed will significantly decreased (Silverthorn, 2004). The potentially disastrous influence of temperature, pH, enzyme concentration, and substrate concentration on enzymes and other proteins is one reason why these modulators are very strictly regulated by the body (Silverthorn, 2004). Temperature, a measure of the intensity of heat, is an important factor in the activity of enzymes. The velocity of an enzymatic reaction is influenced by temperature. This is because substrates collide with active sites frequently in the presence of rapidly moving molecules. In addition, although these molecules do move rapidly the speed of the reaction drops sharply. In short, thermal agitation causes protein molecules (enzymes) to denature ( breakdown of protein structures). All enzymes have an optimal temperature at which reaction rates go fastest without denaturing the enzyme (Campbell and Reece, 2002) pH, a measure of hydrogen ion...
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...violet color is apparently due to the cupric ions with the unshared electron pairs of four nitrogen atoms. All substance is proportional to the number of peptide bonds give the test and the intensity of the purple color produced id proportional to the number of peptide bonds present. Ninhydrintest Amino acids react with ninhydrin (tryketoninhydrindene hydrate) to yield CO2, NH3and aldehyde containing one less carbon than the amino acid. The reaction is also yields a blue or purple color useful for the colorimetric determination of amino acids. X anthoproteictest This test is positive for proteins and amino acids containing an aromatic side chain (phenylalanine, tyrosine, and tryptophan). The benzene ring undergoes nitration with concentrated HNO3giving nitro derivatives which are yellow in color. Phenylalanine does not response readily to this test and requires H2SO4 as catalyst. Millon-Nassetest The phenolic group of tyrosine reacts with Millon-Nasse reagent (HgSO4 in H2SO4) forming an old rose or pink to red complex upon heating. The complex is probably the mercury salt of the phenolic compound Sakaguchi Reaction The guanidinium group of arginine in alkaline solution gives an orange or red color with alpha-naphthanol and sodium hypobromite. Hopkins-Cole test The indole ring of tryptophan reacts with Hopkins-Cole reagent (glyoxylic acid) and sulfuric acid to produce a violet or red purple color Objectives 1. To carry out the different color reaction...
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...McDonald’s but also steakhouses such as Longhorn and Logan’s Roadhouse. Whether you choose to cook your cheeseburgers at home on the grill or grab one on the go, cheeseburgers are an American tradition that everyone can enjoy. However, not all who devour this scrumptious piece of American history actually know the chemistry behind the ingredients that come together to make this delicious masterpiece. A cheeseburger would not exist without the bun to hold all of the ingredients together. The bun is made of flour, a starch or long chains of sugars molecules known as polysaccharides, yeast, salt and water. Flour, or grains are comprised mainly of wheat. When these ingredients mix, the flour gums up and absorbs all the water to produce a protein matrix called gluten. Gluten is elastic and holds the bread together to give it structure. As you knead the dough, the yeast, a living single cell creature, begins to eat the starch. When the starch is consumed by the yeast, carbon dioxide is produced. The process of microbes producing gas from starches and sugars is known as fermentation. When the CO2 gas is heated, it expands, making the bubbles inside the dough larger and inflates the elastic gluten. When the dough is placed in an oven at 400°F, the yeast become more active and produce CO2 faster. But when it becomes too hot, the yeast microbes die and expansion stops. The air pockets set and give the buns a...
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...catalysts in the regulation of chemical and biological reactions in humans and other species. Every organ in humans depends on enzymes, as they are essential for optimal health. Most enzymes are protein molecules, which increase the reaction rate and function best under optimal conditions or temperatures related to the environment and the host organism where the enzyme is found. In this experiment, the digestive enzyme amylase was used in order to determine the optimal temperature for enzyme function from human and fungal (Aspergillus oryzae) sources in various temperatures. The digestive enzyme amylase that will be tested is responsible for the breakdown of the polysaccharide starch into the monosaccharide maltose. In addition, using Iodine as a test marker for the presence of starch, the ability of amylase to break down starch to maltose was also investigated. In the presence of starch, Iodine turns from yellow to black. To that end, human saliva, containing amylase, and fungal amylase were each added to separate test tubes along with a mild starch solution and placed at various temperatures as follows, 0C, 40C, 60C and 95C. The mixture of amylase and starch was then plated onto spot wells containing Iodine as a marker for starch which yielded a color reaction based on the amount of starch versus the break down product, maltose. The results showed that human amylase functions optimally at 40C as demonstrated by an abrupt color change from black to yellow signifying the quick breakdown...
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...1. BIOCHEMISTRYLABORATORY(Midterm)Geromil J. Lara, RMT, MSMT 2. ACTIVITY 1A /1B Subcellular Components of the Living Cell• 5% Trichloroacetic Acid – Suspending medium – Able to precipitate proteins – Good fixative and preservative 3. ACTIVITY 1A /1B Subcellular components of the Living Cell• Sediment 1 – Nuclear Fraction – Nuclei and Unbroken Cells• Sediment 2 – Mitochondria• Sediment 3 – Microsome – Proteins, Enzymes, Inorganic Ions 4. ACTIVITY 1A /1B Subcellular components of the Living Cell• Qualitative Tests – Carbohydrates • Molisch Test • Benedict’s Test – Proteins • Biuret Test • Xanthoproteic Test – Lipids • Sudan Test • Acrolein Test 5. ACTIVITY 1A /1B Subcellular Components of the Living Cell• Carbohydrates – Molisch Test 5 drops of the supernate + Molisch Reagent shake Layer with 1 mL conc. H2SO4Control: 1% LecithinMolisch Reagent: α-Naphthol dissolved in Ethanol 6. ACTIVITY 1A Subcellular components of the Living Cell• Carbohydrates – Molisch Test 5 drops of the supernate + Molisch Reagent shake Layer with 1 mL conc. H2SO4Principle: when sugar solution is mixed with alpha- naphthol is brought in contact with conc. H2SO4, a violet ring is formed at the junction of the 2 liquids 7. ACTIVITY 1A Subcellular components of the Living Cell• Carbohydrates – Molisch Test 5 drops of the supernate + Molisch Reagent shake Layer with 1 mL conc. H2SO4H2SO4 : acts as dehydrating agent forming furfural derivatives which interact with alpha-naphthol liberating a colored compound ...
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...Key Organs and Enzymes of the Digestive System 1) The salivary glands produce salivary amylase to digest starch. 2) The stomach produces pepsin, which is a protease to digest protein. 3) The pancreas produces: Proteases, to digest protein within the small intestine Pancreatic amylase to digest starch within the small intestine Pancreatic lipase to digest fats the small intestine Part 1: Testing for Macromolecules Hypotheses Food 1 (Junk):maruchan instant soup Food 2 (Junk): Frito chips Food 3 (Junk): Waffle Grahams Food 4 (Healthy): Dried oatmeal’s Food 5 (Healthy): sweet n salty mix Food 6 (Healthy): Banana Directions for Testing 1) Why is it important to use a negative and positive control? It is important to have negative and positive...
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...Enzymes are partially or wholly proteins which help catalyze enzymatic reactions. As hypothesized, catechol oxidase (enzyme) was not able to function in a very acidic pH (pH 2) or a highly basic pH (pH 11). In both cases the catechol oxidase activity was decreased which resulted in minimum production of benzoquinone (product). Even though the original hypothesis was not completely supported, however, as seen in figure 1, the absorbance for the mixture is at its highest when the reaction occurs in the presence of a pH 8 buffer, which is close to the pH 7 originally hypothesized. The catechol oxidase is affected by the different pH concentration, and its most favorable pH value is pH...
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...ANTISERUM”) CONTAINS RABBIT ANTI-COW ALBUMIN ANTISERUM ANTI-COW ALBUMIN ANTIBODIES If we were to create anti-human albumin antibodies, why would they interact with serum albumin from animals other than humans? ANTI-HUMAN ALBUMIN ANTIBODIES mixed with serum albumin from.. HUMAN! CHIMP! GORILLA! BABOON STRONG! reaction HORSE! OX! DEER WEAK! reaction CHICKEN! FROG NO! reaction closely related to distantly related to somewhat related to WESTERN BLOT An immunodiagnostic procedure used to detect (with extremely high specificity) particular proteins in a mixed solution, extract, or homogenate. Native proteins are separated via gel electrophoresis, then transferred to a membrane where they are stained and hybridized with specific conjugated antibodies. Also called PROTEIN IMMUNOBLOT procedure. General Procedure 1. Electrophoresis of sample. 2. Preparation of membrane/blotting of gel. 3. Staining of nitrocellulose blot. 4. Primar y antibody reaction. 5. Color development. Preparation of Nitrocelluose Membrane Nitrocellulose membrane Separated Proteins Gelatin Primary antibody Secondary antibody (Color Development Solution) HRP catalyzes a conformational change in chloronaphthol PHLOEM (e.g. chloronaphthol; TMB) Fluorescent: secondary antibody conjugated with a light-emitting fluorochrome. Enzymatic: secondary antibody conjugated with a enzymes such as HRP. Other applications Diagnostics: HIV Confirmatory...
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...NaOH→CH3COONa + H2O Thus change in pH is minimized BUFFER OF THE BODY FLUIDS Cellular metabolism predominantly yields acids so it is approcipriate that body buffer has buffering capacity to absorb acids are first line of defense against acid load. a Bicarbonate buffer system ( H2CO3/NaHCO3) % of buffering capacity, Plasma- 65% Whole body- 40% CO2 and H2CO3 can freely diffuse across the cell membrane and vascular capillary epithelium. Regulation, Base constituents-kidney (metabolic component) Acid constituents –respiration (Respiratory) Salt / Acid – 20 b. Phosphate buffer system (Na2HPO4/NaH2PO4) Primary intracellular buffer, its concentration in plasma is vary low Salt /Acid-4 c. Protein buffer systems Buffering capacity of proteins depends on the pKa value of ionizable side chains. The most effective group is histidine imidazol group with pKa value 6.1 * Albumin -16 histidine * Hemoglobin -38 histidine BUFFER SYSTEM OF THE BODy Extracellular fluid | Intracellular fluid | Erythrocyte fluids |...
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...COMPOSITIONS OF THE CELL 1.CARBOHYDRATES 1.2.3. Task2-Chemical Detection of Starch Duration (mins) | Color of spot | Explanation | 0 | | _ For amylose (the polysaccharides that is present most in the rice suspension), the core of the helix structure easily accommodate iodine which is in Lugol solution). This complex has the deep blue color._ However, the helix structure (to be more specificly, the glycosidic bonds) is easily wrecked by heat (boiling temperature of water) and acid treatment (HCl). Once the helix structure of homopolycarbohydrate is broken, the conformation with iodine no longer exists. It leads to the gradual loss of blue color. | 2 | | | 4 | | | 6 | | | 8 | | | 10 | | | | No color change | | Color of Lugol | | | 2.PROTEINS 2.2.2. Task-Qualitative Detection of Proteins Protein solution | Original color | After 10% NaOH | After 0.5% CuSO4 | 1. Egg albumin | Colorless | Colorless | Blue->purple | 2. Fresh cow milk | White | White | Blue->purple | Explanation: NaOH doesn’t react with Proteins, so there’s no change to the protein solutions Next, when CuSO4 is added, it reacts with NaOH to form Cu(OH)2 (blue) first. 2NaOH+ CuSO4 -> Cu(OH)2(s) + Na2SO4 Then Cu(OH)2 and Proteins together form the complex, which gives out the purple color. This reaction (called biuret reaction) is useful to detect the protein presence. (write down the chemical equation, GOOGLE) 3. LIPIDS 4. NUCLEIC ACIDS 4.1.General...
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...Cindy Rodriguez Professor. Mascarano Biology Lab Fall 2014 Determining the properties of an enzyme Abstract: To determine the properties of an enzyme, a peroxidase, turnip extract is used in this experiment Enzymes are large proteins that are responsible for the speed at which chemical reactions they are involved in taking place. Enzymes speed up chemical reactions by lowering the activation energy of a reaction, the amount of energy necessary to trigger a reaction .Using Peroxidase ,Turnip extract which is expermitnatal easy to prepare and examime that is This experiment determines the effects that concentration temperature, ph, boiling have on an enzymes ability to perform its work. It is hypothesized that none of these variables will have any effect on the activity of the enzyme. Introduction : This expermient with present various temperates and ph levels to be teste in order to determine the properties of an enzyme. An enzyme is a protein that acts as a catalyst, that changes the rate of a reaction with no help of energy. Enzymes lower the activation energy of a reaction the amount of energy necessary to trigger a reaction. Most enzymes are proteins that have a unique shapes which are determined by their amino acid sequences.The shape of the enzyme called the active site determines its catalytic effects. The active site of each type of a unique shape that allows the enzyme to bind with only certain kinds of enzymes called the...
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...BIO 566 INTRODUCTION TO BIOPHYSICS QUIZ 2 MAC-JULY 2012 Question 1 Write an essay on spectroscopy which includes : (15 marks) Basic principles, nature of electromagnetic radiation, types of spectra-(absorbance, emission and fluorescene) types of spectroscopy – (principle, instrumentation and applications of atomic absortion spectroscopy, UV Visible Spectroscopy, Nuclear Magnetic Resonance Spectroscopy and Electron Spin Resonance Spectroscopy) Spectroscopy is the study of the absorption and emission of light and other radiation by matter, as related to the dependence of these processes on the wavelength of the radiation. More recently, the definition has been expanded to include the study of the interactions between particles such as electrons, protons, and ions, as well as their interaction with other particles as a function of their collision energy. Spectroscopic analysis has been crucial in the development of the most fundamental theories in physics, including quantum mechanics, the special and general theories of relativity, and quantum electrodynamics. Spectroscopy, as applied to high-energy collisions, has been a key tool in developing scientific understanding not only of the electromagnetic force but also of the strong and weak nuclear forces. The basic principle shared by all spectroscopic techniques is to shine a beam of electromagnetic radiation onto a sample, and observe how it responds to such a stimulus. The...
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