Chemical Reactions Make Life Possible!

Chemical Reactions Proceed as Follows: ReactantsProducts Energy must be added to “activate” the reaction and break the bonds between atoms

Under Normal Conditions, a High Amount of Energy is Needed to Start a Reaction Energy of Reactants Energy of Products Activation Energy In cases like this (High AE), reactions would occur too slowly to support life!!!

Catalysts speed up the rate of a reaction by lowering the activation energy needed to get the reaction going Catalysts are not changed or used up during a reaction!

A Catalyzed Reaction… Energy of Reactants Energy of Products Activation Energy Requires less energy to get started!!!

The Living Cell has Special Molecules Which Act as Catalysts……. Protein Biomolecules Protein Biomolecules Specific to a Substance or ReactionSpecific to a Substance or Reaction Speeds up Biological Reactions to 10,000,000,000 Times FasterSpeeds up Biological Reactions to 10,000,000,000 Times Faster

Bind to Specific Reactants to Form a Complex Reactants called Substrates Substrate Binds to the Enzyme at the Active Site

E + S ES E + P Important Enzyme: Catalase Breaks H 2 O 2 into H 2 O and O Hydrogen Peroxide is Toxic to Cells Catalase + H 2 O 2 Complex Catalase + H 2 O + O Enzymes use “induced fit” to help bonds form or break between compounds

Enzymes are named by taking either the name of the substrate or the action performed and adding the ending “ase” DNA Polymerase DNA Polymerase Lactase Lactase Ligase Ligase

Temperature: temp = rateTemperature: temp = rate temp = rate temp = rate ***Temperatures too high or low will denature the enzyme! pH: Measure of Solution (0-14) Neutral (pure water) = 7 Acids are less than 7, bases more than 7 Acids are less than 7, bases more than 7 ***Each enzyme has its own range of optimal pH