1. Warm up
Draw an example of a monosaccharide What type of macromolecule is this? Draw an example of a fatty acid What type of bonds hold together amino acids? What type of macromolecule does amino acids make?

2. Enzymes

3. What Are Enzymes?
Most enzymes are Proteins (tertiary and quaternary structures)
Act as Catalyst to accelerates a reaction
Not permanently changed in the process

4. Enzymes Are VERY specific for what they will catalyze Are Reusable
Names end in –ase
-Sucrase
-Lactase
-Maltase

5. How do enzymes Work?
Enzymes work by weakening bonds which lowers activation energy
Activation energy is the amount of energy needed to start a reaction

6. Enzymes Without Enzyme With Enzyme Free Energy
Progress of the reaction
Reactants
Products
Free energy of activation

8. Enzyme-Substrate Complex
The substrate is the substance (reactant) an enzyme acts upon
Enzyme
Joins
Substrate

9. Active Site
The active site is a restricted region of an enzyme molecule which binds to the substrate.
Active Site
Enzyme
Substrate

10. Induced Fit
A change in the shape of an enzyme’s active site (H+ and ionic bonds are involved).
Induced by the substrate.
Enzyme
Active Site
substrate
induced fit

11. What Affects Enzyme Activity?
Three factors:
1. Environmental Conditions
2. Cofactors and Coenzymes
3. Enzyme Inhibitors

12. 1. Environmental Conditions
1. Extreme Temperature are the most dangerous
- high temps may denature (unfold) the enzyme.
2. pH (most like pH near neutral)
3. Ionic concentration (salt ions) – the active site has a slight charge to it

13. 2. Cofactors and Coenzymes
Inorganic substances (cofactors - zinc, iron) and vitamins (coenzymes) are sometimes need for proper enzymatic activity.
Example:
Iron must be present in the quaternary structure - hemoglobin in order for it to pick up oxygen.
Vitamins are precursors to coenzymes.

14. Two examples of Enzyme Inhibitors
a. Competitive inhibitors: are chemicals that resemble an enzyme’s normal substrate and compete with it for the active site.
Enzyme
Substrate
Competitive inhibitor

15. Examples of competitive inhibitors:
Caffeine in your brain – prevents the release of a chemical that slows down brain activity
Antivirals used to treat HIV – interfere with HIV’s ability to reproduce itself

16. Inhibitors b. Noncompetitive inhibitors:
Inhibitors that do not enter the active site, but bind to another part of the enzyme causing the enzyme to change its shape, which in turn alters the active site.
Enzyme
Noncompetitive
Inhibitor
Substrate
active site
altered

17. Examples of noncompetitive inhibition
ATP turns off enzymes that produce ATP
Sulfa drugs that destroy microorganisms