Enzymes

What Are Enzymes? Most enzymes are Proteins Act as a biological Catalyst to speeds up a reaction Not permanently changed in the process

Enzymes Are specific for what they will catalyze Are Reusable End in –ase -Sucrase -Lactase -Maltase

Real Life Enzyme Example Pepsin is an enzyme in the stomach Protein is the substrate Amino acids are the products

How do Enzymes Work? Enzymes work by weakening bonds which lowers activation energy- the energy to get a reaction going

Enzymes Without Enzyme With Enzyme Free Energy Progress of the reaction Reactants Products Free energy of activation

Enzyme-Substrate Complex The substance (reactant) that an enzyme acts on is the substrate Forms an enzyme –substrate complex Enzyme Joins Substrate

Active Site Active site is the restricted region of an enzyme molecule which binds to the substrate. Active Site Enzyme Substrate

Induced Fit Induced fit is a change in the shape of an enzyme’s active site Induced by the substrate Enzymes and substrate fit together like a “handshake”. Each slightly changing to make the fit better once they come into contact with each other

Induced Fit Inducted fit is a change in the configuration of an enzyme’s active site (H+ and ionic bonds are involved). Induced by the substrate. Enzyme Active Site substrate induced fit

Summary of How Enzymes Work The substrate and the enzyme bond together. A reaction occurs that changes the substrate into something new ( a product). The enzyme is NOT changed and recycles to react again with a new substrate molecule.

Enzymes are sensitive to their environment DENATURING ENZYMES – when enzymes lose their structure so they don’t work prNotice the process is often reversible when favorable conditions are re-established.

What Affects Enzyme Activity? 1.Extreme Temperature (hot & cold) are the most dangerous - extreme temps may denature (unfold) the enzyme. Example: high fever 2. pH level (most enzymes like 6 - 8 pH near neutral)

Summary: Enzymes are proteins that act as catalysts. Catalysts are molecules that speed up reactions without being changed or used up. Enzymes have an active site where the substrate binds to form the product. Enzymes can be denatured by changes in the environment. Enzymes work by lowering the activation energy of the reaction.