PPT-16.5 Enzymes Enzymes are proteins that act as biological catalysts.

On the surface of an enzyme a small region called an active site binds a substrate and catalyzes a specific reaction for that substrate Learning Goal Describe enzymes and their role in enzymecatalyzed reactions. Apoenzymes. , . Holoenzyme. , . Abzymes. , . Synzyme. , . Ribozyme. , . Extremozyme. , Historical Development in . Enzymology. , . Characteristics of enzymes, Enzyme Vs Chemical Catalysts. , Enzyme mechanism & Activation Energy, Enzyme Specificity, Fischer and . ENZYMES (DR. NUGENT) I. INTRODUCTION TO ENZYMES/CATALYSTS a. Definition: enzyme = biological catalyst (catalyst = speeds rate of reaction) b. Features of enzymes: i. Enzymes speeds up the rate of a re 2. The Michaelis-Menten equation describes the initial reaction velocity as a function of substrate concentration.. When v. o. = ½ V. max. , K. M. =[S]. Thus, K. M. is the substrate concentration that yields. Baseline (Flightpath D): To be able to define the terms ‘catalyst’ and ‘enzyme. ’.. Further (Flightpath C&B ): To be able to describe the properties of enzymes. To use the lock and key theory and collision theory to explain enzyme action. CATALYSTS AND ENZYMES. What are catalysts?. Simply put, catalysts are substances which, when added to a reaction, increase the rate of reaction by providing an alternate reaction pathway with a lower activation energy (Ea).. Are specific for . what they . catalyze . and do not permanently change during reactions. End in the word -. ase. Function of Enzymes. Enzymes work by lowering the activation energy (the amount of energy needed to start a reaction). . IMPORTANCE. OF ENZYMES. Enzymes are biological catalysts that:. . I. ncrease. . reaction rates . by lowering the amount of energy needed for the reaction to occur. 100-1000x . faster. !!!. Activation Energy. 1. What are enzymes?. Each enzyme has only one specific reaction it can perform. . 2. How many different reactions can a single enzyme perform?. Yes, the same enzyme molecule can be used over and over. Part 1. . Chapter 3. Learning outcomes. You should be able to:. explain how enzymes work. describe and explain the factors that affect. enzyme activity. use V. max. and K. m. to compare the affinity of different enzymes for their substrates. Enzymes. Back when we discussed proteins, we learned that one critical function of protein was to speed up chemical reactions.. Enzymes. are the proteins that increase the rate of chemical reactions. caesin. , . Proteolytic. enzymes (. papain. , . bromelain. , . serratiopeptidase. , . urokinase. , streptokinase, pepsin). UNIT V . PHARMACOGNOSY. DR NISHA SHARMA. ENZYMES . Enzymes are the proteins which act as biological catalysts.. that . catalyze. (. i.e.. , . increase or decrease the rates. of) . chemical reactions. .. . In enzymatic reactions, the . molecules. at the beginning of the process are called . substrates. , and they are converted into different molecules, called the . Today’s Objectives. Describe a general enzyme-catalyzed reaction. Discuss the relation of temperature and pH to rate of reaction in an enzyme-catalyzed reaction. Explain how chemical reactions are affected by enzymes. enzymes. . . The . substance converted by an enzyme is called a . substrate. , and a substance resulting from the conversion of the substrate is called the . product. . . The . enzyme is not consumed during the reaction catalyzed by it, so one enzyme molecule is involved in the conversion of many substrate molecules .