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
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.
This experiment involved the chosen enzyme, B-Galactosidase, to be tested with a substrate called o-nitrophenol-B-D-galactopyranoside (ONPG). The purpose was to determine over time the effects the enzyme had on the substrate concentration, as well as to examine the effect of lactose, a disaccharide on the formation of o-nitrophenol. The experiment utilized a spectrophotometer to determine at which the rate that the enzyme catalyzes, by timing the change in absorbance every 15 seconds, as well as observing any colour change. The amount of enzyme added to the B-Galactosidase is increased over time, and the ONPG is set to a constant value each trial. It was determined that through the trials of testing the absorbance of the enzyme, the faster
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
An enzyme is protein that acts as a catalyst. Catalyst is a chemical agent that increases a chemical’s reaction rate by decreasing the activation energy (initial energy). In this experiment we used Turnip Peroxidase as our enzyme. It was primarily designed to find out if changing different factors such as, the enzyme concentration, temperature, pH and an inhibitor could have an effect on the enzyme’s activity.
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
This lab was designed to study the generation of β-Galactosidase over a 2 lab period, so it got 2 sections; first part was to measure the levels β-galactosidase produced in E.coli K12 cells specifically using IPTG a molecular biology reagent to determine the time of induction of the lac operon. The second part of this experiment was to observe the effects of alternative inducing agents, glucose and antibiotic addition on the induction of β-galactosidase in E.coli K12; this experiments goal was to detect the effect of alternate induction agents, antibiotic and glucose adding on to inducing of β-galactosidase in E.coli. The β-galactosidase is normally switched off in E.coli except in the presence of lactose; the enzyme β-galactosidase breaks down lactose into galactose and glucose. (Matthews 2005). The lac operon or lactose operon is essential for the transportation of lactose in E.coli.
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.
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.
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.
The starch-iodide complex forms because of the transfer of charge between the starch and iodide ion and results in spacing between the energy levels. This allows the complex to absorb light at different wavelengths resulting in a dark blue colour (Travers et al., 2002). A blue colour would indicate a positive test while a yellow colour would show a negative test. The Benedict’s test is useful for reducing sugars.
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.
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).
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
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
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.