What Are Enzymes? Proteins, with complex 3-d shapes Have an active site which can bind a substrate (reactants)

Help Chemical Reactions Occur Notice the enzyme is not used up in the reaction! Only a certain substrate will fit in the active site

How? Allows bonds in substrate to be broken more easily, with less input of energy

Another Example

Reaction Energy Diagrams Activation Energy

Input of energy required to break initial bonds and begin the reaction Even if reaction will release energy

Enzymes Lower Ea Make the transition state easier to reach

Endergonic vs. Exergonic

Specificity of Active Sites Enzymes only catalyze substrates with a complementary shape Any changes to the shape of the enzyme will disable the activity of the active site