Enzymes Actual Enzyme Molecule Simplified Model What are

Enzymes Actual Enzyme Molecule Simplified Model

What are enzymes? • Substances that speed up chemical reactions without being used up by the reaction. • Also called biological catalysts. • Almost all enzymes are proteins with very specific shapes. Soo. . . where are they made? ________

How do enzymes work? • Substrate: substance that binds to enzyme, fitting in like a puzzle piece • Active site: region of the enzyme where the substrate binds. • Lock and key model: – A single enzyme is able to speed up one specific chemical reaction. – The shape of the active site precisely fits the shape of the substrates.

How enzymes work cont…. Animation of enzymes at work

What can affect enzyme reaction rates? • Concentration of enzyme: – Increasing enzyme concentration – more enzymes will increase the enzyme reaction rate. • Concentration of substrate: – More substrate - the enzyme reaction rate also increases.

p. H effects reaction rates • Each enzyme has an optimal p. H that helps maintain its specific shape. – Changes in p. H may denature (change shape of) enzymes

Temperature also effects enzymes • Most enzymes have an optimum temperature that produces the fastest reaction rate. Humans = 98. 6˚F > Animation • A higher temperature generally results in an increase in enzyme activity. > Animation • Beyond optimum temperature enzymes begin to change shape or break apart (denature) and no longer work > Animation 1 > Animation 2

Temperature and Enzyme Activity

• Most enzymes end in “-ase” and usually take on the prefix of the substance that they are acting on: • Maltose + water glucose + glucose the enzyme that breaks down maltose is maltase Malt + ase = maltase -

• Examples: What do each of the following act on? 1. 2. 3. lipase – protease – lactase –