Lab: Enzyme Activity Under Various Environmental Conditions
Introduction:
The name of the enzyme used in this lab is called peroxidase. “In plants the enzyme is called peroxidase. A related enzyme named catalase performs the same function in animals” (Pearce, 2017). These enzymes breakdown hydrogen peroxide (which is a by – product of metabolism).
In this lab “the behaviour and activity of these enzymes” will “be measured by adding enzyme extract to hydrogen peroxide and then monitoring the rate of gaseous oxygen produced” (Pearce, 2017). The disk indicates action because time is recorded for how long it takes to float, meaning that gas is being produced that pushes the disk upwards. Therefore, the average rate of gaseous oxygen produced can be measured.
Enzymes have a quaternary structure as they are globular proteins and have a 3D shape. The primary structure is made up of amino acids joined by peptide bonds. The secondary structure is made up of an alpha helix/beta helix pleated sheet as a result of hydrogen bonding in the backbone. The tertiary structure is made up of 3D polypeptides due to bonding of the “R” group and the Quaternary structure is made up of 2/more polypeptides joined together (globular proteins). “The 3D shape allows the enzyme to have an active site – this is where the substrate (what is being acted on) binds to the enzyme” (Pearce, 2017). Hydrogen peroxide (in this case the substrate) binds to the activation site on the peroxidase (enzyme). When
In this experiment, the naturally occurring peroxidase is extracted from homogenized turnip (Brassica rapa) pulp (Coleman 2016). Its role in the environment is to remove toxic hydrogen peroxide during metabolic processes where oxygen is used (Coleman 2016). The goal of this experiment is to evaluate the change of absorbency of turnip peroxidase within a metabolic reaction utilizing oxygen. Any change noted is indicative of the peroxidase removing hydrogen peroxide. Within this experiment, the extract will be prepared, the amount of enzyme will be standardized, and the effect of changing the optimal conditions will be observed. If the enzyme concentration is increased then the rate of the reaction decrease. If the pH of solutions used is increased
The preparation for the experiment started by gathering the solutions of enzyme Peroxidase, substrate hydrogen peroxide, the indicator guaiacol and distilled water. Two small spectrometer tubes and three large test tubes with numbered labels. In addition, one test tube rack, one pipet pump and a box of kimwipes were also gathered. Before the experiment, the spectrometer must be set up to use by flipping the power switch to on. Following, the machine was warmed up for 10 minutes and the filter lever was moved to the left. In addition, I set the wavelength to 500 nm with the wavelength control knob. Before the experiment, I had to create the blank solution by pipetting 0.1 ml of guaiacol, 1.0 ml of turnip extract and 8.9 ml water into tube #1. Following the creation of the blank, a control 2% solution was created.
Sulfuric acid - was used to stop the reaction with catalase and hydrogen peroxide. It denatured the enzyme (catalase) and halted the reaction so the amount of hydrogen peroxide decomposed could be measured.
The hypothesis is that catalase activity will increase exponentially with higher concentrations of hydrogen peroxide until all catalase active sites are filled, in which case the
If another enzyme like lactase is used, no reaction would take place because the substrate, hydrogen peroxide, wouldn’t fit into the active site.
The purpose of this experiment was to simply measure oxygen production rates released from decomposed hydrogen peroxide under different conditions (concentration of enzymes, temperature, and PH level).
The data in proves that our hypothesis was correct. When we increased the temperature to 35°C, the the enzyme activity increased because kinetic energy increased, increasing the collisions between the substrate and the enzyme, and thus creating a higher chance of reaction. When we increased the temperature to 45°C, the enzyme activity decreased as the enzyme became denatured,because the atoms in the enzyme had enough energy to overcome the hydrogen bonds between the R groups that give the enzyme its shape From our data, we could conclude that the optimal temperature of turnip peroxidase is around 35°C and around 45°C, it will start to denature.
In the first part of the enzyme lab, we mixed a substrate and an indicator with an enzyme. There was also a neutral buffer in each of the chemical mixtures. The neutral buffer regulated the pH to around 7. We got a color palette and once we mixed each together, we observed and saw a change in the color of the substance. The darker and more brown the substance got, the more oxygen produced by the reaction. Our results showed that amount of oxygen produced increased about 10% a minute until it sort of equilibrated at 4 minutes and didn’t change to the fifth minute mark. If we were to change anything we did in the experiment, we would make our comparisons to the chart more precise. Overall we thought it
We hypothesized that a medium pH buffer added to the hydrogen peroxide an peroxidase reaction would be the best condition for the enzyme activity due to it being the more neutral than the high, being basic, and low, being acidic, pH.
An Enzyme is a protein, which is capable of starting a chemical reaction, which involves the formation or breakage of chemical bonds. A substrate is the surface or material on or from which an organism lives, grows, or obtains its nourishment. In this case it is hydrogen peroxide. This lab report will be explaining the experiment held to understand the effects of the changes in the amount of substrate on the enzyme’s reaction.
The purpose of this experiment is to learn the effects of a certain enzyme (Peroxidase) concentration, to figure out the temperature and pH effects on Peroxidase activity and the effect of an inhibitor. The procedure includes using pH5, H202, Enzyme Extract, and Guaiacol and calibrating a spectrophotometer to determine the effect of enzyme concentration. As the experiment continues, the same reagents are used with the spectrophotometer to determine the temperature and pH effects on Peroxidase activity. Lastly, to determine the effect of an inhibitor on Peroxidase, an inhibitor is added to the extract. It was found that an increase in enzyme concentration also caused an increase in the reaction rate. The reaction rate of peroxidase increases at 40oC. Peroxidase performed the best under pH5 and declined as it became more basic. The inhibitor (Hydroxy-lamine) caused a decline in the reaction rate. The significance of this experiment is to find the optimal living conditions for Peroxidase. This enzyme is vital because it gets rid of hydrogen peroxide, which is toxic to living environments.
5ml pipettes graduated in 0.1 ml units with suction devices or automatic pipetters and tips
will be working at the pH 7 the majority of the time and our bodies
Abstract: Enzymes, catalytic proteins that at as catalysis which makes the process of chemical reactions more easily. There are two main factors that actually affects enzymes and their functions which are temperature and pH. Throughout this experiment, the study how pH and peroxidase affects each other and the enzyme was made. The recordings of how the enzymes responded when it was exposed to four different pH levels to come up with an optimum pH which was predicted in the hypothesis and the IRV at the end.
Enzymes are a specific kind of protein that usually act to enhance a chemical reaction. Enzymes, like any other protein, are made of amino acids arranged in a specific pattern that in transcribed through mRNA and translated in the nucleus by the ribosomes. The basic amino acid chain is called the primary structure, the chain usually undergoes bonding that results in either an Alpha helix structure or a Beta sheet structure depending on the function of the enzyme and the interactions between the amino acids. Further interaction will result in a 3D conformation which is called a tertiary structure, which are the functioning subunits of an enzyme. As subunits come together to form an enzyme, that is a quaternary structure.