1.1 Abstract The purpose of quantitative analysis of protein using a spectrophotometer is to measure the concentration of proteins in a given sample. The experiment is conducted by laboratory method (Biuret Test) and using spectrophotometer to analyze the absorbance of reactants at 540 nm, hence determining the concentration of the proteins in a given sample. The purpose of stopped enzyme assay to study B-galactosidase is to determine the effect of temperature and concentrations of substrate on enzyme activity. B-galactosidase breaks down the disaccharide lactose into simple sugars glucose and galactose. However, glucose is a colorless compound hence it has to be substituted with a compound that is detectable by a visible color change. Hence, …show more content…
Enzymes speed up chemical reactions enabling more products to be formed within a shorter span of time. Enzymes are fragile and easily disrupted by heat or other mild treatment. Studying the effect of temperature and substrate concentration on enzyme concentration allows better understanding of optimum conditions which enzymes can function. An example of an enzyme catalyzed reaction is enzymatic hydrolysis of an artificial substrate, o-Nitrophenylgalactoside (ONPG) used in place of lactose. Upon hydrolysis by B-galactosidase, a yellow colored compound o-Nitrophenol (ONP) is formed. By using a spectrophotometer to measure absorbance at 420 nm, the rate of enzyme activity after all reactions have come to a stop can be …show more content…
However, all proteins are constructed from the same set of 20 amino acids linked in unbranched polymers. The covalent bond that exists between amino acids is called peptide bond, hence a polymer of amino acids is named polypeptide. A protein is a biological functional molecule made up of one or more polypeptides which is folded and coiled into unique three-dimensional structure. In laboratory, it is important to measure the concentration of proteins for research investigations. Biuret test is adopted to quantify proteins in fluid by using a spectrophotometer. The biuret solution is a blue solution made up of sodium hydroxide and copper (II) sulfate which turns pink or violet in the presence of proteins, peptides and compounds containing 2 or more peptide linkage. A spectrophotometer measures the respective amounts of light consisting of different wavelengths absorbed and transmitted by a pigment solution. Spectrophotometer works when white light is separated into lights of different wavelengths by a prism which different colors of light passes through the sample. The transmitted light strikes a photoelectric tube, converting light energy to electric current that is measured by a galvanometer. The transmittance reading measures the absorbance of reactants and determine the concentrations of protein
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The objective of this lab was to determine the best pH level to increase enzyme activity. As this objective was met, it was discovered that water (pH level 7) was the best for percent absorbance. The hypothesis for this experiment was, “If peroxidase is an enzyme and therefore contains certain pH tolerances, then when placed in solution with pH levels of three, seven, and ten and the reaction is measured by a colorimeter, then water will be the optimal solution for maximum reaction rate.” As seen in the tables and graphs, the data supported the hypothesis due to the fact that most enzymes have an optimal pH of 4-9.
The substrate for beta-galalactoside is ortho-nitrophenyl-B-galactoside. ONPG is structured similarly to lactose. The purpose of the experiment was to add a competitive inhibitor to observe if the reaction rate would slow down. A competitive inhibitor is when the inhibitor binds to the active site on the enzyme and prevents the binds of the substrate
Sucrase activity increases with increasing sucrose concentration Materials and Methods Effect of pH on Enzyme Activity 1. Dependent Variable amount of product (glucose and fructose) produced 2. Independent Variable pH 3. Controlled Variables temperature, amount of substrate (sucrose) present, sucrase + sucrose incubation time Effect of Temperature on Enzyme Activity 1.
LABORATORY REPORT Activity: Enzyme Activity Name: Natalie Banc Instructor: Elizabeth Kraske Date: 09.22.2016 Predictions 1. Sucrase will have the greatest activity at pH 6 2. Sucrase will have the greatest activity at 50 °C (122 °F) 3. Sucrase activity increases with increasing sucrose concentration Materials and Methods Effect of pH on Enzyme Activity 1. Dependent Variable amount of product (glucose and fructose) produced 2.
Testing for the Presence of Macromolecules in McDonald’s Happy Meals Clayton Wagoner MST Biology White 4 duPont Manual High School Introduction Carbohydrates, lipids, proteins, and nucleic acids are organic molecules found in every living organism. These macromolecules are large carbon based structures. The macromolecules are assembled by joining several smaller units, called monomers, together through a chemical reaction called dehydration synthesis. The resulting polymer can be disassembled through the complementary process called hydrolysis.
1% glucose, 1% maltose and 1% lactose all progressively get positive results by changing colours to reddish brown at the end of this experiment. In this case the aldehyde functional group that is present in the products (monosaccharides and some disaccharides) in this reaction is able to reduce copper in the presence of alkali and this produces colour changes while converting to an aldose sugar. Honey is made of fructose and glucose which instantly turned brown after the test-tube was placed in the boiling water because of its active aldehyde and carbonyl group. The copper (II) sulphate present in the Benedict’s solution reacts with electrons from the aldehyde group which results in a redox reaction to from cuprous oxide, a red brown precipitate that seen in all of the above mentioned solutions (Hill, 1982). Beer also gave positive results because it contains aldehydes and ketones (i.e. acetone, trans-2-butenal, furfual) during its beer production process where the sugars are converted through fermentation (Hill, 1982).
The effect of pH on the speed of enzyme interaction with substrate chemicals Hypothesis: About pH: If the pH level is less than 5, then the speed of the enzyme reaction will be slower. About temperature: If the temperature stays the same, then the speed of the enzyme reaction will not be completely affected. Background information: The function of enzymes is to speed up the biochemical reaction by lowering the activation energy, they do this by colliding with the substrate.
Set the wavelength to 470 nm, this is to measure the tetraguaiacol. Set the spectrophotometer to zero by using a blank. The blank should contain 13.3 mL of distilled water, 0.2 mL of guaiacol, and 1.5 mL of enzyme extract in a clean test tube. After, transfer a portion of this mixture into a cuvette, cover the top of the cuvette with Parafilm and then place the cuvette into the spectrophotometer and set it to
These enzymes have a secondary and tertiary structure and this could be affected by increases and decreases in temperature beyond the optimum temperature of the enzyme to work in. Mostly enzymes are highly affected any changes in temperature beyond the enzymes optimum. There are too
ABSTRACT: The purpose of the experiments for week 5 and week 6 support each other in the further understanding of enzyme reactions. During week 5, the effects of a substrate and enzyme concentration on enzyme reaction rate was observed. Week 6, the effects of temperature and inhibitor on a reaction rate were monitored. For testing the effects of concentrations, we needed to use the table that was used in week 3, Cells.
By observing figure 3, the more enzyme that is available, the faster the reaction rate is. The optimal enzyme concentration was chosen based on the R2 values from figure 2. The highest observable rate also had the best R2 number, which was closest to one. This enzyme concentration was used in part 2.
Introduction: Enzymes are biological catalysts that increase the rate of a reaction without being chemically changed. Enzymes are globular proteins that contain an active site. A specific substrate binds to the active site of the enzyme chemically and structurally (4). Enzymes also increase the rate of a reaction by decreasing the activation energy for that reaction which is the minimum energy required for the reaction to take place (3). Multiple factors affect the activity of an enzyme (1).
Catalase Activity on Substrate Based On Gas Pressure Production Rate Name of the Class Author’s Name Date Enzymes are organic compounds which act as catalysts and speed up biological reactions in biological organisms. They are not destroyed or changed during the reaction but rather they are used over and over again to catalyze many more reactions. Their activity may be affected and altered by factors such as temperature, substrate concentration, enzyme concentration and Ph.
Introduction 1.1 Aim: To determine the kinetic parameters, Vmax and Km, of the alkaline phosphatase enzyme through the determination of the optimum pH and temperature. 1.2 Theory and Principles (General Background): Enzymes are highly specific protein catalysts that are utilised in chemical reactions in biological systems.1 Enzymes, being catalysts, decrease the activation energy required to convert substrates to products. They do this by attaching to the substrate to form an intermediate; the substrate binds to the active site of the enzyme. Then, another or the same enzyme reacts with the intermediate to form the final product.2 The rate of enzyme-catalysed reactions is influenced by different environmental conditions, such as: concentration
Bio Chem lab Report 04 Enzyme Biochemistry Group Member: Chan Man Jeun Duncan (16002621) Law Sze Man (16000478) Introduction Enzyme is a protein base structure substance in our body. It works at a biocatalyst that will catalyzing the chemical reaction, which helps to speed up the chemical reaction. Enzyme could only function in specific shape, and the shape of enzyme is depending on the environment, therefore it is hard for an enzyme to function well in an extreme environment. The aim of this experiment is to see can the enzyme functions normally in different environment(pH, temperature and salt concentration) via using starch solution, amylase from saliva, 0.5M HCl solution, 0.5M NaOH solution and NaCl solution, and using iodine solution