5.5

Enzymes are proteins that speed up specific reactions in cells:

• Activation energy is the energy needed to start a chemical reaction
• Catalysts can start a chemical reaction by giving activation energy without destroying the cells
• A main catalyst is enzymes
• the enzyme doesn't actually start the reaction it just lowers the temperature needed so that it happens on its own
• Enzymes work on substrates : A specific reactant
• and the area in the enzyme the reaction occurs is the active site
• another way this may work is that it holds the reactants together until they react
  

Concept Check:
1. Explain the role of activation energy. How does an enzyme affect this?
Activation energy allows a chemical reaction to take place and enzyme lowers the energy needed to start the reaction
2.Describe how a substrate interacts with an enzyme.
The substrate is a reactant that goes into the active site