Enzymes: The Details Fall 2023 PDF

Enzymes The Details  What is the link between digestion, photosynthesis, bread, wine and laundry detergent? What’s the missing link? They all depend on enzymes.  Enzymes are protein molecules, and so are made up of amino acids. Most enzyme...

Enzymes The Details  What is the link between digestion, photosynthesis, bread, wine and laundry detergent? What’s the missing link? They all depend on enzymes.  Enzymes are protein molecules, and so are made up of amino acids. Most enzymes contain between 100 and 1,000 amino acids. These amino acids are joined together in a long chain, which is folded to produce a unique 3D structure. Every What are enzyme has a high specificity for the substrate it acts enzymes on. made of?  Enzymes are biological catalysts – they speed up the chemical reactions that take place inside all cells, but without being used up in the process. There are many thousands of different types of enzyme, and each one catalyses a different reaction. What are Enzymes occur naturally in all organisms, but they are enzymes? increasingly being used in industrial processes.  Enzymes catalyse the thousands of reactions that need to take place in order to maintain life. What are some of these reactions? digestion respiration Enzymes and photosynthesis cells (plants and some bacteria) protein synthesis. Examples on digestive enzymes Examples on digestive enzymes Enzymes are used in the food industry  Go to Chat GPT and use the prompt: “What are 3 different examples of synthetic Synthetic Enzymes are enzymes, and how are they used?” Used in the medical industry and in other fields of technology  Enzymes Lower a Reaction’s Activation Energy All chemical reactions require some amount of energy to get them started. OR It is First push to start reaction. This energy is called activation energy.  Enzymes speed up reactions by lowering the activation energy (Ea) of a reaction. The activation energy is the energy needed to start a reaction. Different reactions have different activation energies. Why do enzymes Ea without enzyme speed up energy (kJ) reactions? Ea with enzyme reaction (time)  When enzymes catalyze a reaction they are not used up Enzymes or chemically changed. properties Can be used to catalyze many reactions.  Enzymes are very specific about which reactions they catalyse. Only molecules with exactly the right shape will bind to the enzyme and react. These are the reactant, or substrate, molecules. The part of the enzyme to Why are which the reactant binds is enzymes so called the active site. specific? This is a very specific shape and the most important part of the enzyme. How enzymes bind to their substrates “Induced Fit model” Enzyme Function enzyme enzyme-substrate enzyme + ↔ complex ↔ + substrate products  The rate of enzyme–catalysed reactions depends on several factors. What are some of these? Factors that affect the rate of a reaction include: temperature substrate concentration Factors pH surface area affecting enzyme concentration. enzymes All enzymes work best at only one particular temperature and pH: this is called the optimum. Different enzymes have different optimum temperatures and pH values.  If the temperature (heat) and pH changes sufficiently beyond an enzyme’s optimum, the function of the enzyme changes. If the shape changes to the point where the active site no longer binds the substrate, then the enzyme is denatured. This is an irreversible shape change and the enzyme can no longer catalyze the reaction. Factors affecting enzymes heat pH denatured normal  The optimum temperature for most of the enzymes is between 37°C - 45°C. Rate of reaction increases with an increase in temperature. Factors affecting Optimum temperature The temp at which rate of enzyme enzymatic reaction occur fastest. reaction (Temperature)  Rate of reaction of an enzyme reaction changes at different temperatures Below optimal temp: colder molecules move slowly, fewer collisions → slower reaction As temp increases, molecules move faster → more frequent collisions → reaction rate increases (KMT) Factors affecting rate of enzyme At optimum temp:, enzymes are working best, reaction highest rates of changing substrate to products(higher kinetic energy, higher chances of (Temperature) collision between substrates and enzymes), higher rates of forming enzyme-substrate complex. Above optimum temp: increased heat alters the 3D structure of enzyme → attractive forces disrupted, active site changes → cannot catalyze reactions  Optimal pH range of different digestive enzymes Factors affecting rate of enzyme reaction (pH)  ►The rate of enzyme catalyzed reaction is directly proportional to the concentration of enzyme. ►As enzyme concentration increases more active sites Factors affecting are available. More enzyme-substrate complexes (if rate of enzyme plenty of substrate are available), form (and so more reaction (Enzyme products are produced). The rate of reaction increases. concentration)  Coenzymes and Cofactors are either small metallic, non-protein, or protein based molecules that bind to an enzyme, helping to make it active. It binds to the active site, then together they can catalyze a reaction by binding to a substrate. (E.g: FAD, NAD, Iron, etc.) Cofactors and Coenzymes Factors affecting rate of enzyme reaction Enzyme Inhibition Factors affecting rate of enzyme reaction Enzyme Inhibition