Courses : Forest Ecology Lecturer :Frischa Adellia Semester : 4thSemester, 2022/2023 Session Enzymatic Reactions Enzymatic reactions refer to biochemical processes in which enzymes act as catalysts to convert substrates into specific products. Enzymes are proteins that have special properties to speed up the rate of certain chemical reactions without undergoing permanent changes in themselves. In an enzymatic reaction, the substrate interacts with the enzyme to form an enzyme-substrate complex, then undergoes transformation into final products, and finally the enzyme is released in the same form as before the reaction started. Some of the main characteristics of enzymatic reactions include: 1. Specificity: Each enzyme has specificity for a certain substrate, meaning that the enzyme will only react with substrates that match its properties. This creates a specific reaction pathway that leads to the desired product. 2. Efficiency: Enzymes can increase the rate of chemical reactions up to millions of times compared to reactions that are not catalyzed by enzymes. This is because enzymes can lower the activation energy required to start a reaction, thereby speeding up the overall reaction. 3. Regulation: Enzyme activity can be regulated in cells to control the rate of biochemical reactions. Regulation can be carried out through various mechanisms, such as modulation of enzyme activity by regulatory molecules or covalent modification of the enzyme itself. 4. Reversibility: Many enzymatic reactions are reversible, meaning enzymes can facilitate the conversion of substrates to products and vice versa depending on environmental conditions and reaction balance. Examples of enzymatic reactions include the hydrolysis of sucrose to glucose and fructose by the enzyme sucrase, or the conversion of pyruvate to acetyl-CoA in the citric acid cycle by the enzyme pyruvate dehydrogenase. Enzymatic reactions are essential in various biological processes, such as energy metabolism, synthesis of biomolecules, and regulation of metabolic pathways in cells. A concrete example of an enzymatic reaction is the hydrolysis of starch by the amylase enzyme. 1. Substrate: Starch, which is a polysaccharide found in foods such as flour. 2. Enzyme: Amylase, which is present in human saliva and produced by the salivary glands. Amylase is an enzyme responsible for breaking down starch into simpler products. 3. Reaction: In this reaction, starch is broken down into simpler glucose molecules. The amylase enzyme acts by catalyzing a hydrolysis reaction, in which the glycosidic bonds between glucose units in starch are broken down by the addition of water molecules. 4. Products: The final products of this reaction are smaller glucose molecules, which can be absorbed by the human body and used as an energy source. This process occurs naturally in the mouth when we chew foods that contain starch, such as bread or rice. The amylase enzyme begins to break down starch into simple sugars as food is chewed, helping to initiate carbohydrate digestion in the human body. In conclusion, an enzymatic reaction is a biochemical process in which enzymes act as catalysts to convert substrates into products at a higher rate and under milder environmental conditions compared to reactions without a catalyst. This process plays an important role in various biological processes, such as metabolism, digestion, and the synthesis of important substances in cells. Several important points that can be concluded about enzymatic reactions include: 1. Enzymes increase the reaction rate by lowering the activation energy required to start the reaction. 2. Enzymes are specific to their substrates, so each enzyme can only react with certain substrates. 3. Enzymatic reactions are reversible, where enzymes can facilitate the conversion of substrates into products and vice versa depending on environmental conditions and reaction balance. 4. Regulation of enzyme activity is an important mechanism in controlling the rate of biochemical reactions in cells. Thus, understanding enzymatic reactions is important in understanding various biological processes and developing applications in the fields of biotechnology and medicine.