Enzymes are proteins that catalyze chemical reactions in cells by lowering the activation energy needed. They have a specific active site structure that allows them to bind to substrate molecules. Denaturing destroys an enzyme's structure by exposure to heat or chemicals, disrupting its active site. Cells use ATP as an energy storing molecule to power cellular work through addition and removal of phosphates. Common cellular reactions include hydrolysis, which uses water to break polymers into monomers, releasing energy, and dehydration synthesis, which removes water and bonds monomers together to store energy.

1. BIOLOGY
Unit 1 Notes:
Enzyme Details
& Cellular
Reactions

2. (1) Enzymes
• Type of protein.
• Have a very specific structure (like a key + lock) to
fit with their substrate (the molecule they are
binding to).
• Used in cells to catalyze chemical reactions:
– Make reactions go faster.
– Lower the activation energy requirement, allowing the
reaction to happen with less energy payment.

5. (2) Enzyme Denaturing
• The substrate must bind exact at a special structure on
the enzyme called the Active Site.
• Denaturing 
– Occurs when enzymes are exposed to extreme heat /
chemicals.
– Causes enzyme to unravel.
• Why Is Denaturing a Problem?
– Unravel = Change in structure
– Change in structure = Messed up Active Site
– Messed up Active Site = No Catalyzing the Reaction

8. (3) Cell Energy
• Cells need to do a lot of work to maintain
homeostasis.
• Work requires energy!!
• ATP = Adenosine Triphosphate
– Energy storing molecule for cells!
• Draw A Picture:

9. ATP = Adenosine + 3 Phosphates
ADP = Adenosine + 2 Phosphates

10. Add a Phosphate
+ Store Energy In
Bonds
Remove a
Phosphate +
Release Energy
From Bonds

11. (4) Cellular Reactions
• Cells use chemical reactions to:
– Break molecules into smaller pieces.
– Make larger molecules.
– Store and Release Energy
• 2 Common Reactions
– Hydrolysis
– Deyhydration Synthesis

12. (5) Hydrolysis
• Hydro = Add Water
Lysis = To Explode / Break Apart
• What Happens?
– Add water to a larger polymer.
– Break it apart into smaller monomers.
– Release energy.
• Draw A Picture:

13. Energy
Add Water
Release Energy
Polymer
Monomers

15. (6) Dehydration Synthesis
• Dehydrate = Remove Water
Synthesis = To Put Together
• What Happens?
– Remove water from smaller monomers.
– Put together (bond) smaller monomer units.
– Store energy.
• Draw A Picture:

16. Monomers
Remove Water
Energy
Store Energy
Polymer