Enzymes & Your Body
By Malinda Pires
Enzymes are Catalyst
• Enzymes speed up
chemical reactions.
•Animation Menu
•Enzymes are catalyst
to over 4000
biochemical reactions!
http://en.wikipedia.org/wiki/File:GLO1_Homo_sapiens_small_fast.gif
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
Activation Energy
Enzymes work by
lowering the
activation energy
needed to start a
chemical reaction.
http://en.wikipedia.org/wiki/File:Activation_energy.svg
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
Enzymes are Reusable
• Enzymes are reusable
molecules found in
living things.
• Animation Menu
http://en.wikipedia.org/wiki/File:GLO1_Homo_sapiens_small_fast.gif
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
Classifying Enzymes
• There are 4 major categories of macromolecules:
carbohydrates, lipids, proteins, & nucleic acids
1 http://en.wikipedia.org/wiki/File:Glucose-2D-skeletal.png
3 http://en.wikipedia.org/wiki/File:Mouse-cholera-antibody-1f4x.png
2 http://en.wikipedia.org/wiki/File:Phospholipids_aqueous_solution_structures.svg
4 http://en.wikipedia.org/wiki/File:Benzopyrene_DNA_adduct_1JDG.png
• Most enzymes belong to the class of proteins.
• However, there are a few catalytic RNA
molecules.
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
Naming Enzymes
• Take the name of the substrate the enzyme works
on and add the suffix -ase
• Example: Lactose → Lactase
http://en.wikipedia.org/wiki/File:Lactase.jpg
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
Enzyme Form and Function
• Lock & key Model: The shape of an enzyme
allows it to do a specific job much like a lock and
key.
• Specificity - Animation Menu
http://en.wikipedia.org/wiki/File:Llave_bronce.jpg
http://en.wikipedia.org/wiki/File:Wardedlock.jpg
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
Induced Fit Model
• Enzymes can form to the shape of its
substrate.
http://en.wikipedia.org/wiki/File:Induced_fit_diagram.svg
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
Denaturing Enzymes
• When an enzyme is denatured it is damaged.
• Denaturing changes the shape.
• Without the correct shape enzymes won’t
function properly.
• HOW are enzymes denatured?
– Temperature Animation Menu
– pH
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
Enzyme Inhibitors
• Chemicals that prevent the enzyme from working.
• Inhibitors decrease the enzyme reaction rate.
http://en.wikipedia.org/wiki/File:Competitive_inhibition.svg
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
Enzyme Activators
• Chemicals that help the enzyme work.
• Activators increase the enzyme reaction rate.
Active
Site
Activator
X
Binding
Site
Substrate
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
Enzymes are used all over your body!
http://en.wikipedia.org/wiki/File:Digestive_system_diagram_en.svg
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
http://upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Major_digestive_enzymes.png/750px-Major_digestive_enzymes.png
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College