Enzymes Honors Biology

Chemical Reactions and Enzymes chemical reaction:

Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products)

Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products) A. example: wood + oxygen  carbon dioxide + water + energy

Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products) A. example: wood + oxygen  carbon dioxide + water + energy Reactants

Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products) A. example: wood + oxygen  carbon dioxide + water + energy ReactantsProducts

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen Reactants

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen ReactantsProducts

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen ReactantsProducts chemical equation: CO 2 + H 2 O  C 6 H 12 O 6 + O 2

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen ReactantsProducts chemical equation: CO 2 + H 2 O  C 6 H 12 O 6 + O 2 Reactants

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen ReactantsProducts chemical equation: CO 2 + H 2 O  C 6 H 12 O 6 + O 2 Reactants Products

Chemical Reactions and Enzymes II. The speed of a reaction depends on whether it releases or absorbs energy. Reactants Products Activation energy Activation energy Reactants Energy Absorbing Energy Releasing

Chemical Reactions and Enzymes A.All reactions require some energy to start: activation energy.

Chemical Reactions and Enzymes A.All reactions require some energy to start: activation energy. B.catalyst: substance that speeds up a chemical reaction by lowering the activation energy

Chemical Reactions and Enzymes A.All reactions require some energy to start: activation energy. B.catalyst: substance that speeds up a chemical reaction by lowering the activation energy Catalysts found in living things are called enzymes Enzymes are made of Proteins

Chemical Reactions and Enzymes C. Enzymes provide a site where the reactants of a chemical reaction can be brought together

Chemical Reactions and Enzymes C. Enzymes provide a site where the reactants of a chemical reaction can be brought together are not used up or changed during the chemical reaction

Chemical Reactions and Enzymes active site: part of the enzyme where the reactants bind (stick)

Chemical Reactions and Enzymes active site: part of the enzyme where the reactants bind (stick) reactants: called substrate when they stick to the enzyme

Chemical Reactions and Enzymes active site: part of the enzyme where the reactants bind (stick) reactants: called substrate when they stick to the enzyme substrate only fits into the active site of the correct enzyme (like a key and lock)

Labeled diagram: Enzyme Active Site Reactants

Enzyme Active Site Reactants III. How does an enzyme work? A. reactant binds to the enzyme Reactant stuck to Active Site

Enzyme Active Site III. How does an enzyme work? A. Reactant binds to the enzyme Reactant stuck to Active Site

Enzyme Active Site III. How does an enzyme work? B. reactants converted to product Product

Enzyme Active Site III. How does an enzyme work? C. products are released – enzyme is free to bind new reactant Product

IV. Enzymes only work in specific conditions A. temperature: destroys the shape of the enzyme (protein) B. pH: changes the shape of the enzyme and its active site

Enzyme Active Site Temperature or pH Change: Product No Product Made

IV. Enzymes only work in specific conditions C. inhibitor molecules: block reactant from entering active site

Enzyme Active Site Inhibitor Molecules: Product No Product Made

IV. Enzymes only work in specific conditions D. coenzymes: make enzymes work better

Enzyme Active Site Enzyme: Peroxidase in liver cells Reactants: Hydrogen peroxide Reactants Hydrogen Peroxide

Enzyme Active Site Enzyme: Peroxidase in liver cells Reactants: Hydrogen peroxide Reactants

Enzyme Active Site Enzyme: Peroxidase in liver cells Products: Water and Oxygen Product O2O2 H2OH2O

Enzyme Active Site Product Enzyme: Peroxidase in liver cells Products: Water and Oxygen More Hydrogen Peroxide O2O2 H2OH2O

Substrate Concentration The reaction rate increases until the enzymes become saturated with substrate, and a maximum rate is reached