 Catalysts-speed up reactions by changing the amount of energy needed to start the reaction  Made of proteins  Do not change themselves during the reaction “helping hands” Catalase- breaks down H 2 O 2 Amylase- breaks down sugars Reactant or substrate Product Anabolic- synthesizes Catabolic- Breaks down Reactions Active site

A enzyme & substrate fit like a lock & key (shape specific) and like a hand in a glove – “induced fit” Active site is where the reactants bind to the enzyme

3  Three factors: 1.Environmental Conditions 2.Cofactors and Coenzymes 3.Enzyme Inhibitors

4 1. Extreme Temperature are the most dangerous 1. Extreme Temperature are the most dangerous - high temps denature (unfold) enzyme. - high temps may denature (unfold) the enzyme. 2.pH (most like pH near neutral) 3.Ionic concentration (salt ions)

5  Inorganic substances (zinc, iron) vitamins enzymatic activity  Inorganic substances (zinc, iron) and vitamins (respectively) are sometimes needed for proper enzymatic activity.  Example: Ironquaternary structure-hemoglobin pick up oxygen. Iron must be present in the quaternary structure - hemoglobin in order for it to pick up oxygen.

6 C ompetitive inhibitors: resemble enzyme’s normal substrate competeactive site C ompetitive inhibitors: are chemicals that resemble an enzyme’s normal substrate and compete with it for the active site. Enzyme Competitive inhibitor Substrate

7 Noncompetitive inhibitors: do not enter the active sitebind to another part enzymeenzyme change its shape alters the active site Inhibitors that do not enter the active site, but bind to another part of the enzyme causing the enzyme to change its shape, which in turn alters the active site. Enzyme active site altered Noncompetitive Inhibitor Substrate

This is a graph of an enzyme reaction. If the conditions are favorable, and there is enzyme and substrate available, the enzymatic reaction will reach its optimal efficiency where the speed of product production can get no faster. If conditions change (such as pH goes outside of enzyme range, temperature goes outside of enzyme range, or concentration of product, enzyme, or substrate changes) the amount of product produced will decrease or stop completely.

Lysosomes -organelles containing enzymes that digest worn out organelles, bacteria, or viruses -when a cell dies its lysosomes burst and break down the cell into macromolecules that are reused by other cells -are part of the Endomembrane system. -The Endoplasmic Reticulum (synthesis and transport) connects with the Golgi Apparatus (molecule packaging) which makes the lysosomes