Chemical Reactions and Chemical Reactions and EnzymesEnzymes

What is a chemical reaction?What is a chemical reaction?

• Changes or transforms chemicals into other chemicals

• Ex: Iron + Oxygen Iron Oxide (rust)

• What is the product?

• What are the reactants?

Energy Is RequiredEnergy Is Required

• Energy can be either given off or absorbed for a chemical reaction to occur

• Identify the type of reaction as either endothermic or exothermic by the graphs to the right:

Activation EnergyActivation Energy

• Energy needed to start a reaction

• Identify the activation energy supplied for the following chemical reactions

1) Building a Fire

2) Turning on a Light

3) Starting a Car

CatalystCatalyst

• Any substance that lowers the activation energy needed to start a reaction.

Enzymes Baby!!!!!!Enzymes Baby!!!!!!

• Describe what enzymes “do” using the graph below:

EnzymesEnzymes

• Enzymes are proteins made by the cell to speed up the chemical reactions.

Properties of EnzymesProperties of Enzymes

1. Lowers activation energy2. Speeds up a reaction3. Can be used repeatedly4. Shape specific (substrate)**If shape is altered, enzyme cannot functionAnimations

http://www.lewport.wnyric.org/jwanamaker/animations/Enzyme%20activity.html

Factors That Affect Enzyme ActivityFactors That Affect Enzyme Activity

• High Temperature (boiling )

• Extreme pH – (acid/base)

• Changes enzyme shape

Denaturing an EnzymeDenaturing an Enzyme

• A change in the shape of the active site on the enzyme

What life molecule are enzymes What life molecule are enzymes a part of???a part of???

PROTEINS!

• Enzymes = speed up reactions (to break down substances)

• Substrate= a molecule which is acted upon by an enzyme (the reactant)

““ase”ase”• Enzymes have an ending “ase”

• It helps you identify which one is the enzyme and which one is the substrate.