Enzymes
Enzymes: Proteins that increase the rate of
chemical reactions
• Enzymes are needed for ALL biochemical reactions
– Building up molecules, breaking down and reorganizing
molecules
• Enzymes are called biological catalysts
– Speed up reactions by lowering the activation energy
• Enzymes
– Reusable (unlimited use unless damaged)
– Specific (only work with certain molecules/ reactions)
• Enzymes are damaged by pH and temperature
– High pH and High temperature
– Causes change in the enzyme’s shape—can no longer bind
or do its job!
Enzyme Function
• Enzymes have active sites where the substrate
(reactant) binds/fits into the enzyme
• When the substrate and active site bind, the enzyme
changes shape
– causing a reaction to happen
Enzyme Function
• Once the reaction occurs the substrate no
longer fits in the enzyme and is released as
product
• Enzyme returns to original shape ready to be
reused again