1. Proteins Making Chemical Reactions Possible
Enzymes
Proteins Making Chemical Reactions Possible

2. 11/30/15 Do Now: Copy down Vocab
Enzyme=special proteins that speed up chemical reactions
Substrate = molecules that enzymes bind to
Active site = area where chemical reactions occur
Anabolism = the building up of molecules
Catabolism = the breaking down of molecules
Denatured = the change of shape of an enzyme due to temperature or pH
Inhibitors = molecules that slow down or stop enzymes

3. Amoeba Sisters Video Fill out worksheet that goes along with video
Biomolecules review
Enzymes

4. Energy and chemical reactions
Most chemical reactions require energy to begin
- the energy required to start a chemical reaction is called activation energy.

5. What are enzymes?
Enzymes are proteins which reduce activation energy allowing chemical reactions to occur in living things

6. Enzymes reduce activation energy

7. Enzymes Act as Biological Catalysts
Catalysts are inorganic molecules that speed up chemical reactions -
Enzymes are organic molecules that speed up reactions in living things
-enzymes are not changed by the reaction they speed up

8. Active Site Enzymes have an area called an active site.
- the active site is where the chemical reaction occurs

9. The Shape of the Enzyme Determines Function
The active site of the enzyme fits with only one type of molecule known as the substrate.
Substrate is the molecule that the enzyme acts on.

10. Enzyme Reactions Catalase + 2H2O2 ES Catalase + 2H2O + O2 Written as :
Enzyme + Substrate Enzyme + Product
Example
Catalase + 2H2O ES Catalase + 2H2O + O2
enzyme substrate enzyme product
enzyme-substrate
complex

11. Lock & Key Model
Substrate fits into the active site like a key into a lock
The enzyme reduces the amount
of energy needed to break apart
the substrate
The products of the reaction
leave and make the enzyme
available for more substrates

12. Enzymes can build molecules
Substrate molecules can only bond one way.
Substrate molecules
fit into the active
site in the best
position to bond
Once in the active site,
the molecules of substrate join together form a new product

13. Enzyme Inhibitors Inhibitors control the rate of enzyme activity
- if there is too much of an enzyme’s product, inhibitors can slow or even stop an enzyme’s activity
Two types of Inhibition
- Competitive Non competitive

14. Competitive Inhibition
The inhibitor is a molecule that can occupy part of the active site
While the inhibitor is in the active site, substrate can’t bind with the enzyme – inhibitors compete with the substrate for the active site
inhibitor competes inhibitor blocks the
with substrate active site

15. Noncompetitive Inhibition
The inhibitor binds with the enzyme at a site away from the active site.
Inhibitor causes enzyme to change shape – prevents
substrate from entering the active site
Inhibitor binds with enzyme Enzyme changes shape keeps
substrate from active site

16. Denatured Enzymes
Enzymes are proteins and if they are exposed to extremes of temp or pH lose their shape
- if a protein loses its shape, it loses its function
- a protein that loses its shape is said to be denatured
- if an enzyme is denatured, substrate can’t enter the active site
extreme
temperature or pH

17. Common Enzymes Amylase - breaks down starch
Catalase – breaks down H2O2
DNA polymerase – joins DNA nucleotides to build DNA
Lipase – break apart fats
Lactase – breaks apart lactose – milk sugar
Protease- breaks apart protein molecules
-What does –ase in a molecules’ name imply?