An enzyme is a globular protein present in living organisms that acts as a biological catalyst, accelerating reactions that occur in the body without being used and without using ATP. This means that an enzyme can be used again and again indefinitely (“Enzyme & Substrate | Bioninja”). Say no to plagiarism. Get a tailor-made essay on "Why violent video games should not be banned"? Get the original essay Enzymes react with the substrate by having an "active site", which is the site where a specific substrate attaches to the enzyme. After attachment to the substrate, an enzyme-substrate complex forms, with the enzyme catalyzing the reaction to form the enzyme-product complex. The product is then released from the enzyme, and the enzyme can continue to catalyze the reactions (“Enzyme Catalysis | Bioninja”). Enzymes are substrate specific; this means that only a specific enzyme can catalyze a specific substrate. Enzymes are extremely important for biological functioning, as they are involved in many processes throughout the body to ensure survival. For example, enzymes are heavily involved in the digestive process, where enzymes such as amylase, protease and lipase break down starch, proteins and fats respectively into smaller molecules to allow for absorption. Without these enzymes, we would not receive the nutrition we need to survive (“Chemical Digestion | Bioninja”). Yeast contains the enzyme catalase, which is produced in the body's liver and breaks down hydrogen peroxide. Hydrogen peroxide is a waste product of metabolism and is toxic to the body. For the body to get rid of hydrogen peroxide, catalase is produced to break down hydrogen peroxide into oxygen in water (“The Health Benefits of Catalase”). Temperature, pH and substrate are essential factors for the functioning of enzymes; at the optimal level, the enzyme will work as quickly as possible. If the optimum is exceeded, the enzyme rapidly denatures, which alters the proteins present in the enzyme and the substrates are no longer able to bind to the enzyme, resulting in a rapid decrease in reaction rate . Temperature allows an increase in the kinetic energy available for the enzyme to move and collide with the substrate molecules. Keep in mind: this is just a sample. Get a personalized article from our expert writers now. Get a Custom Essay High temperatures cause the enzyme to destabilize and destabilize. disrupts hydrogen bonds within enzymes, thereby denaturing the enzyme. pH changes the solubility of proteins and changes the overall shape of the enzyme. The enzyme must therefore be in a solution with the correct pH, otherwise it will not be able to catalyze the reaction. The concentration of the substrate increases the reaction rate due to the increased number of substrate molecules with which the enzyme collides. The reaction rate will increase until the enzyme reaches the saturation point, where it functions at its optimal level ("Enzyme Activity | Bioninja").