Scope, Sequence, and Coordination

A Framework for High School Science Education

Based on the National Science Education Standards


Catalysts and Enzymes

Catalysts and Enzymes
CATALYSTS, SUCH AS METAL SURFACES, ACCELERATE CHEMICAL REACTIONS. CHEMICAL REACTIONS IN LIVING SYSTEMS ARE CATALYZED BY PROTEIN MOLECULES CALLED ENZYMES.


Further Description:

Catalysts can be categorized into heterogeneous (surface) and homogeneous (solutions). Comparisons can be made between these two types of catalysts regarding the way they facilitate the reorganization of atoms and molecules as the reaction proceeds. The addition of a catalyst lowers the activation energy of the forward and reverse reactions equally so that the equilibrium concentration remains unchanged.


Concepts Needed:

Grade 9

Catalyst, solution, enzymes, reaction rate

Grade 10

None suggested

Grade 11

Activation energy, reaction coordinate, equilibrium, adsorption, reversible reaction

Grade 12

Homogeneous catalyst, heterogeneous


Empirical Laws or Observed Relationships:

Catalysis


Theories or Models:

Chemical bonds, catalytic theory


Page 72 in

Micro-Unit Description:

Catalysts and Enzymes
Students should observe the decomposition of hydrogen peroxide. Adding manganese dioxide, they should observe the rapid evolution of a gas. They should also observe other examples of catalysts and their effects on chemical reactions, including the action of yeast in fermentation as an example of the action of an enzyme.


National Science Teachers Association
1840 Wilson Boulevard
Arlington VA 22201-3000
703.243.7100
www.nsta.org