1. Chemical Reactions and Enzymes Notes

2. Objectives What happens to chemical bonds during chemical reactions?
Explain the effect of a catalyst on activation energy.
Why are enzymes important to living things?

3. Vocabulary Chemical reaction Reactant Product Activation energy
Catalyst
Enzyme
Substrates

4. Chemical Reaction
A process that changes, or transforms, one set of chemicals into another.

5. Reactants
The elements or compounds that enter into a chemical reaction.

6. Products
The elements or compounds produced by a chemical reaction.

7. Chemical reactions always involve changes in the chemical bonds that join atoms in compounds.

8. Activation Energy
The energy that is needed to get a reaction started.

9. Catalyst
A substance that speeds up the rate of a chemical reaction.

10. Enzymes
Proteins that act as biological catalysts.

11. Enzymes speed up chemical reactions that take place in cells.

12. The micrograph shows a white blood cell engulfing an invading pathogen.
(Colored SEM; magnification about 3000X)
The larger micrograph shows a pathogen after it has been captured. Once inside a white blood cell, enzymes are used to destroy the pathogen.
(Colored TEM; magnification 11,000X)

13. Substrates
The specific reactants that an enzyme acts on.

14. Substrates bind to an enzyme at certain places called active sites.
The enzyme brings substrates together and weakens their bonds.
The catalyzed reaction forms a product that is released from the enzyme.

15. Enzymes are proteins that catalyze biochemical reactions
Enzymes are proteins that catalyze biochemical reactions. The activities of enzymes depend on the temperature, ionic conditions, and the pH of the surroundings.