enzymes honors biology chemical reactions and enzymes chemical reaction:

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

Reactants Products

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

Reactants Products

Chemical Reactions and Enzymes

B. example:

carbon dioxide + water glucose + oxygen

Reactants Productschemical equation:

CO2 + H2O C6H12O6 + O2

Chemical Reactions and Enzymes

B. example:

carbon dioxide + water glucose + oxygen

Reactants Productschemical equation:

CO2 + H2O C6H12O6 + O2

Reactants

Chemical Reactions and Enzymes

B. example:

carbon dioxide + water glucose + oxygen

Reactants Productschemical equation:

CO2 + H2O C6H12O6 + O2

Reactants Products

Chemical Reactions and Enzymes

II. The speed of a reaction depends on whether it releases or absorbs energy.

Reactants

Products

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 cellsReactants: Hydrogen peroxide

ReactantsHydrogen Peroxide

Enzyme

Active Site

Enzyme: Peroxidase in liver cellsReactants: Hydrogen peroxide

Reactants

Enzyme

Active Site

Enzyme: Peroxidase in liver cellsProducts: Water and Oxygen

Product

O2 H2O

Enzyme

Active Site

Product

Enzyme: Peroxidase in liver cellsProducts: Water and Oxygen

More Hydrogen Peroxide

O2

H2O

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