The Effects of Temperature and Specificity on the Activity of Enzyme
Afomia Zewdie
BIOL-1406-S4L Lab
June 30, 2016
Abstract
This experiment was performed in order to determine how the condition of the environment and the specificity can affect enzymatic activity. The activity of enzyme, how efficiently the enzyme functions, is affected by general environmental factors, such as temperature and PH. It can also affected by chemicals that specifically influence that enzyme. In condition of low temperature environment, the enzymes activity will be low. As the temperature raises the rate of an enzyme-catalyzed reaction increases. The optimal temperature of an enzyme is where the temperature that the enzyme works best. Enzyme specificity is the ability of enzyme to choose exact substrate from similar molecules. Lactase is an enzyme found in small intestine that catalyzes the breakdown of Lactose (milk sugar) into the simple sugars glucose and galactose. In this experiment the enzyme Lactase and its’ substrate Lactose were used to measure the production of Glucose. This experiment will examine the specificity of an enzyme to only a specific substrate and the amount of glucose production in different temperature.
Introduction
An enzyme is a macromolecule that acts as a catalyst, a chemical agent that speeds up a reaction without being consumed by the reaction. Enzymes speed up energy by lowering activation energy barrier. They break down molecules called substrates.
Enzyme = any one of many specialized organic substances, composed of polymers of amino acids, that act as catalysts to regulate the speed of the many chemical reactions involved in the metabolism of living organisms. (Microsoft® Encarta® Encyclopedia '99.)
1. An enzyme is a macromolecule that acts as a catalyst and also speeds up reactions.
2. We measured 1 mL of turnip peroxidase (the enzyme) and 3 mL of neutral buffer (pH corresponding to the test tube number i.e. pH 5 in test tube 5) with a syringe and disposed it into tubes 3, 5, 6, 7, 8, and 10
In the initial part of the experiment, the materials used were: cuvettes, broad-range pH paper, dry watch glass, a spectrophotometer, parafilm, transfer pipette, solution E (solution B and distilled water), sodium carbonate, hydrochloric acid, and solution D (enzyme ALP high concentration). The experiment was initiated by preparing solution E. Solution E was formed by adding 6.5 mL of distilled water (dH20) with 6.5 mL of solution B (para nitro phenolphosphate - pNPP). A total of four cuvettes were labeled control 1, acidic 2, neutral 3, and 4 basic (Wilson, et al 2015). Each cuvette contains a specific pH with the exception of the control cuvette as shown in Table
In order to understand how enzymes work, it is important to know what a catalyst is. A catalyst is a substance that enhances the rate of a chemical reaction without undergoing any irreversible chemical change at the end of the reaction (Chemicool). An enzyme is a protein that functions as a catalyst during chemical reactions. In order for chemical reactions to occur, a certain amount of energy in what is known as the activation
We then tested the last set of test tubes containing milk and lactase, we did this to find which ones would present the most glucose concentration results, when placed in different temperatures, 4°C, boiling and room temperature. What we wanted to know was how far temperature could affect lactase to perform its enzymatic activity. We hypothesized that if the lactase is placed in a high or low temperature outside its active range, the temperatures would have a negative impact on the functions of the enzyme. If the temperature has an affect on lactose then we would see some temperatures in which lactase will be function able. We came to a conclusion that enzymes work at a temperature that is closest to body temperature (25°C); boiling water (100°C) denatures the enzyme, while the enzyme is not able to function properly if
Purpose To determine the temperature at which the potatoes catabolic enzymes breakdown H2O2 (hydrogen peroxide) the fastest. Hypothesis If the temperature of the H2O2 is 35.7 degrees Celsius, then it will break down the fastest because that is the temperature enzymes work in the human body Materials -Ice Bath -Observation
Enzymes are molecules that accelerate the rate of a reaction through the lowering of the activation energy necessary to perform the reaction without their presence. Depending on the environment that the enzyme is in, determines how efficient the enzyme will be in accelerating the reaction. Factors such as pH and temperature play a role on the enzyme’s efficiency and overall success of the reaction. For example, having a high temperature can break apart non-covalent interactions within proteins—the most common form of an enzyme. The breaking down of these bonds would result in the enzyme having a conformational change that does not allow the substrate to fit into its active site. In our experiment, we used the enzyme cellobiase in order to study
First Day: Water Extraction of the Enzyme In a 400-mL beaker, wheat germ (50 g) and cold distilled water (200 mL) were added. The beaker was placed in an ice bath and the wheat germ solution was stirred for 30 minutes. The wheat germ solution was transferred to a centrifuge bottle and it was centrifuged for 10 minutes. After centrifuging, the wheat germ solution was measured in a graduated cylinder and transferred into a clean centrifuge bottle, discarding the pellet (PI). The supernatant I (SI), containing the enzyme, was placed in the freezer.
The results from this experiment show the effects that concentration, pH and temperature have on enzyme activity. In part A, three different concentrations of enzyme solutions were tested. The undiluted enzyme had the fastest enzyme activity, the 1:9 dilution had the slowest enzyme activity and the 1:3 dilution fell in between the undiluted one and the 1:9 dilution. This result showed that the undiluted enzyme converts the amylose at a faster rate. Increasing enzyme concentration will increase the rate of reaction because more active sites are available to bind to substrate and more enzymes will be colliding with substrate molecules (Berkson 1937).
Enzyme catalysis is dependant upon factors such as concentration of enzyme and substrate, temperature and pH. These factors determine the rate of reaction, and an increase in temperature or pH above the optimum will
Hypothesis: If the temperature increases, then rate of the chemical reaction will increase as well, and if the temperature decreases, then the rate of reaction will also decrease.
The purpose of this lab report is to investigate the effect of substrate concentration on enzyme activity as tested with the enzyme catalase and the substrate hydrogen peroxide at several concentrations to produce oxygen. It was assumed that an increase in hydrogen peroxide concentration would decrease the amount of time the paper circle with the enzyme catalase present on it, sowing an increase in enzyme activity. Therefore it can be hypothesised that there would be an effect on catalase activity from the increase in hydrogen peroxide concentration measured in time for the paper circle to ride to the top of the solution.
In this lab or experiment, the aim was to determine the following factors of enzymes: (1) the effects of enzymes concentration the catalytic rate or the rate of the reaction, (2) the effects of pH on a particular enzyme, an enzyme known and referred throughout this experiment as ALP (alkaline phosphate enzyme) and lastly (3) the effects of various temperatures on the reaction or catalytic rate. Throughout the experiment 8 separate cuvettes and tubes are mixed with various solutions (labeled as tables 1,3 & 4 in the apparatus/materials sections of the lab) and tested for the effects of the factors mentioned above (concentration, pH and temperature). The tubes labeled 1-4 are tested for pH with pH paper and by spectrophotometer, cuvettes 1a-4a was tested for concentration and cuvettes labeled 1b-4b was tested for temperature in four different atmospheric conditions (4ºC, 23ºC, 32ºC and 60ºC) to see how the enzyme solution was affected by the various conditions. After carrying out the procedures the results showed that the experiment followed the theory for the most part, which is that all the factors work best at its optimum level. So, the optimum pH that the enzymes reacted at was a pH of 7 (neutral), the optimum temperature that the reactions occurs with the enzymes is a temperature of 4ºC or
Enzymes are catalytic proteins that act to speed up chemical reactions that occur in our bodies and in the bodies of many other organisms by reducing the amount of activation energy required in order for a reaction to occur. Without enzymes, the chemical reactions that take place in all organisms would take place too slowly to keep the organism alive. Since all enzymes are proteins, and protein’s functions are dependent on their structure, enzymes require certain conditions to maintain their perfect structure. The disorder of structure and function of an enzyme is known as denaturation. Certain factors such as temperature, pH, enzyme concentration, and substrate concentration have certain effects on enzyme activity. To investigate the effects of these different conditions, an experimental investigation was set up to test the four different variables and their effect on the enzyme catecholase as it catalyzes catechol, the solute. Results can be seen on Figures A – D.