Biology Investigatory Project Effect of Catalase Enzyme in Plants Done by : Harish Rao B Grade XII A Roll. No 15 National Public School Banashankari CERTIFICATE This is to certify that Harish Rao B of Grade XII has successfully completed the Biology Investigatory Project titled “Effect of Catalase Enzyme in Plants” as prescribed by the CBSE for the year 2023 – 2024. Date : _________________ Signature of Teacher : _______________ Signature of Principal : _____________ AISSCE Code No. : ______________________ Signature of Examiner : ____________________ Acknowledgements I would like to thank our principal, Jayanthi Nair Ma'am, Vice principal, Shreelata Sharma ma’am, biology teacher Neetu Ma'am and all other faculty who have given us this opportunity and made it possible to do this project. I also thank my parents and peers, as they have helped me push forward and complete this assignment on time with excellence. Sl. No. 1. Index Title Page Introduction 4 2 Experimental Theory and Procedure 8 3 Experimental Evidence (Images) 4 Bibliography 10 Introduction An enzyme is a chemical substance that acts as a catalyst in most biological reactions. They are mainly proteinaceous substances that affect the rate of the reactions in organisms and are necessary in every such reaction. They speed up metabolic pathway action to such an extent that the products formed and disintegrated are enough to sustain the organism’s life. The study of enzymes is called enzymology. Enzymes act on certain molecules which are called substrates. Enzymatic action is substrate-specific, and usually acts on select substrates only and they act by reducing the activation energy required by a chemical reaction. They can do so because of their unique three-dimensional structure. This 3-D structures enables them to possess a slot in their structure called the active site, to which the substrate attaches itself. Enzymes can be classified into 4 types based on their structure : - Primary Structure of Enzymes : These enzymes have a simple long linear structure and have the most basic orientation. - Secondary Structure of Enzymes : These enzymes are two-dimensional and each part is held by hydrogen bonds and are mainly of the types :- beta-pleated sheet and alpha helix - Tertiary Structure of Enzymes : These are three-dimensional and are the minimal structures required to catalyse any kind of enzyme. - Quaternary Structure of Enzymes : It is a type of enzyme and the most common type of enzyme that shows an active site and resembles many tertiary enzymes coiled. Although most enzymes are proteins, there are exceptions to this rule. There exist RNA-based enzymes too and are called Ribozymes. One of the most important ribozymes, Ribonuclease P, is used to catalyse the process of transcription, one of the most crucial steps in the Central Dogma of Molecular Biology. This enzyme catalyses the formation of RNA from DNA in eukaryotic and prokaryotic cells. Based on the different types of substrates enzymes act on, they can be classified broadly into : 1. Ligases : Ligases are a family of enzymes that catalyse joining of two chemical compounds by formation of new chemical bond. 2. Lyases : Lyases are a class of enzymes that catalyse the breaking of bonds between compounds by means apart from that of oxidation and hydrolysis. 3. Oxidoreductases : Oxidoreductases are a category of enzymes that catalyse reduction and oxidation reactions that take place in an organism. 4. Transferases : This class of enzymes catalyses reactions in which a particular functional group from one molecule is transferred to another compound. 5. Isomerases : These are enzymes that catalyse reactions where the compound is converted from one isomer to another. 6. Hydrolases : These enzymes catalyse reactions in which substances are broken down into multiple fragments within which water is removed. Any typical has an appearance as given below : . The given structure is a quaternary structure which catalases the breakdown of maltose sugar into two molecules of glucose Enzymes may help in speeding up metabolic pathways, but these enzymes’ active site is competed over and when a substance apart from the substrates combines with the enzyme (which is not supposed to happen), occurs a phenomenon called inhibition. Because of inhibition, the enzyme is not allowed to combine with the enzyme to form products. Inhibition is very harmful and can cause death in certain cases. For example, upon taking consumption of cyanide, there is inhibition of the Mitochondrial electron transport chain (Complex IV) and causes the ATP oxidation to stop. This ultimately causes the death of the organism. Experimental Theory and Procedure AIM : : To study the action of catalase enzyme in plants. MATERIALS : One potato, hydrogen peroxide (H 2O2), glass beakers/cups. PROCEDURE : 1. Divide the potato into three roughly equal segments. 2. Boil one segment of the potato and make sure all cells are heat-killed; store in beaker. 3. Put the one other segment in the freezer for at least 1 hour, and store in beaker. 4. Leave one segment of the potato out in the open inside a beaker. 5. After above instructions, add hydrogen peroxide to all 3 beakers with potato segments. OBSERVATION : There is seen to be a formation of foam after leaving the set up for a while. This foam is the oxygen gas being liberated due to catalase enzyme action. This enzyme is seen to decompose hydrogen peroxide(which is considered to be a harmful substance) into water and oxygen. It is also seen that bubbling and foaming is maximum in the sample left out in the open, when compared to the samples that have been frozen and heat-killed. This is because, in the heatkilled sample, there are no living cells remaining to synthesize the enzyme; for the frozen sample, the optimum temperature for enzymatic action is not achieved and hence, the enzyme is not fully efficient, and there are traces of bubbling. RESULT : Catalase enzyme is present in living cells, with its optimum temperature range being close to room temperature and is a hydrolase enzyme, which is made to decompose toxins present in the organism. Experimental Evidence Bibliography 1. Wikipedia - Enzyme 2. https://www.education.com/science-fair/article/activator/ 3. Google Images
