Enzymes

Enzymes Review If You Think You Need It! Watch this video if you think you are having a hard time with enzymes. What are Enzymes? A catalystis a substance that speeds up a chemical reaction.Enzymesare biological molecules (typically proteins) act as a catalyst for chemical reactions that take place within cells. They are vital for life and serve a wide range of important functions in the body, such as aiding in digestion and metabolism.Some enzymes help break large molecules into smaller pieces that are more easily absorbed by the body. Other enzymes help bind two molecules together to produce a new molecule. Enzymes are highly selective catalysts, meaning that each enzyme only speeds up a specific reaction.The specific action of an enzyme with a single substrate can be explained using aLock and Keyanalogy first postulated in 1894 by Emil Fischer. In this analogy, the lock is the enzyme and the key is the substrate. Only the correctly sizedkey (substrate) fitsinto thekeyhole (active site)of thelock (enzyme).Smaller keys, larger keys, or incorrectly positioned teeth on keys (incorrectly shaped or sized substrate molecules) do not fit into the lock (enzyme). Only the correctly shaped key opens a particular lock. This is illustrated in the graphic below: Label the parts! Enzyme, Substrate, Active site, Product Substrate Enzyme Active Site Product Product How does an enzyme-substrate-complex resemble a lock and key? The substrate is a specific shape like a key that only fits in the specific lock (enzyme) The enzyme is a specific shape like a key that only fits in the specific lock (substrate) I have no idea what you are talking about. The substrate is a specific shape like a key that fits in any lock like a master key. Naming Enzymes Most enzymes are easy to spot, as they commonly end with -ase. It is also usually easy to guess what substrates they work on depending on the first part of the name. For example, Sucrase is an enzyme that works on sucrose and Lipase works on lipids.Not all enzymes are like this, however. For example, the enzyme that breaks down starches is called Amylase. Fun fact: Amylase is in your spit. It is what helps break down food in your mouth. When you put bread in your mouth, you should notice that it will break down on its own. This is because the Amylase enzymes start breaking down the bread without you even chewing! Identifying sugars and enzymes Drag and drop the names of sugars and enzymes to their correct spots! Sugars Lactose Galactose Maltose Sucrose Enzymes Lactase Amylase Maltase Sucrase How Enzymes Affect Activation Energy Remember that enzymes are catalysts. Activation energyis the energy needed to activate a chemical reaction.Enzymes speed up reactions by lowering the activation energy of a reaction. They do this by binding to a substrate and holding it in a way that allows the reaction to happen more easily.In the chart above, the blue line represents the reaction WITHOUT enzymes and the green line represents the reaction WITH enzymes. As you can see the reaction WITH the enzymes requires much less energy. Activation Energy Based on the graph above what can be concluded about activation energy? Select all that are true. Without an enzyme more activation energy is required. Without an enzyme less activation energy is required. With an enzyme less activation energy is required. With an enzyme more activation energy is required. Optimal Conditions Enzyme activity can be affected by a variety of factors, such as temperature, pH, and concentration. Enzymes work best within specific temperature and pH ranges, and sub-optimal conditions can cause an enzyme to denature, or lose its ability to bind to a substrate.Temperature (Chart a): Raising temperature generally speeds up a reaction, and lowering temperature slows down a reaction. However, extremely high temperatures can cause an enzyme to lose its shape (denature) and stop working. The optimal temperature is the highest temperature that makes enzymes better before they start getting bad, so the TOP of the curve. The optimal temperature in the chart below is 35 degrees.pH (Chart b): Each enzyme has an optimum pH range. Changing the pH outside of this range will slow enzyme activity. Extreme pH values can cause enzymes to denature. As with temperature, the optimal pH range is when the enzyme is performing at its best. The optimal pH in the chart below is a pH of 7.Concentration (Chart c): Concentrationis just how much of something you have in one place. Increasing enzyme or substrate concentration will speed up the reaction, as long as there is not to many. If the concentration gets too high, it will not hurt the enzyme, it just will not become any more productive. As the chart shows below, the production just balances, it does not go back down. Enzyme Practice 1 An experiment was performed to test the effect of temperature and pH on the activity ofEnzyme X. The following data was collected during the experiment:Use the data to answer the following questions: 1) What is the optimum pH of enzyme X? 7 8 9 10 2) What is the optimum temperature of enzyme X? 10 20 30 40 3) Enzyme X performs critical life functions. Use the data above to explain why a fever of 40 degrees may be dangerous: It will make the enzyme move too fast, which will burn the person. It will cause the enzyme to denature, which means it will get bigger. It will cause the enzyme to denature, which means it will stop working. I will turn the enzyme into DNA, which will make it stop working. Using the 2 graphs above, at what pH do the following enzymes work best?Sucrase: 4Lipase: 8Pepsin: 3Trypsin: 8 Vocabulary Enzyme A protein that is a catalyst for chemical reactions. Catalyst A substance that speeds up a chemical reaction Optimum Temperature or pH at which the enzyme works best Denature When the active site of an enzyme changes so that the substrate no longer fits. Substrate the substance on which an enzyme acts. Active Site the specific region of an enzyme where a substrate binds Product the substance that enzymes turn substrates into Enzymes are proteins that reduce the activation energy of a chemical reaction in our bodies AND increases the rate of reaction. Enzymes are necessary in life in order to maintain homeostasis (internal balance). Substrates are the substances that bind to enzymes and products are the substances that are made after the chemical reaction happens. Enzymes have certain conditions that they work their best in. In order for enzymes to work properly, they must be in an environment with an optimal pH and temperature. If an enzyme is NOT in optimal conditions, it can become denatured, which distorts its shape and the substrate can no longer bind to it.