Ths general biology unit 2 our bodies cell reactions and enzymes notes_v1516

1. BIOLOGY
Unit 2 Notes:
Cell Reactions &
Enzymes

2. (1) Cellular Reactions
• Cells use chemical reactions to:
– Break molecules into smaller pieces.
– Make larger molecules.
– Store and Release Energy.

3. (2) Cell Energy
• Cells need to do a lot of work to maintain
homeostasis.
• Work requires energy!!
• Cells use ATP and ADP in order to release and store
energy from the phosphate bonds as needed:
– ATP = Adenosine Triphosphate
– ADP = Adenosine Diphosphate
• Draw A Picture:

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

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

6. (3) 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.

9. (4) 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 change structure and 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