ENZYMES

ENZYMES: Speedy Proteins!

IMPORTANCE OF ENZYMES Enzymes are biological catalysts that: Increase reaction rates by lowering the amount of energy needed for the reaction to occur 100-1000x faster!!!

Activation Energy

Lowering Activation Energy

IMPORTANCE OF ENZYMES Enzymes are biological catalysts that: are NOT changed or used up DO NOT participate in the reaction, simply make the reaction go faster

ENZYME STRUCTURE Active Site: Site where reactant binds to enzyme Substrate: The reactant the enzyme can work on

The substrate fits like a “key” into the enzyme’s “lock” (active site). Enzymes are very specific about which types of substrates they can work on.

Turn to a partner Explain why only the red shape will work in this enzyme. Include the terms enzyme, substrate, active site, and specific.

Most enzymes are named after the substrate they work on (usually ending in “-ase”). Lactose (substrate) Peptide bonds (substrate) Lactase (enzyme) Peptidase (enzyme)

Product Chemical produced by the reaction.

Turn to a Partner

Enzymes can bind substrates together …Or break them apart

“Adding” small units together, making large molecules Anabolism “Adding” small units together, making large molecules

Catabolism Breaking up large molecules into smaller ones

Factors that affect enzyme activity

COENZYMES Substances that help the enzyme do its work EX:vitamins

INHIBITORS Substances that interfere with the action of the enzyme EX: poisons, toxins

2 Types of Inhibitors

Noncompetitive Inhibitors Do NOT block the active site but bind at a different site causing the shape of the active site to change so the substrate can no longer bind.

Competitive Inhibitors Block the active site so the substrate cannot bind.

Denaturing Changes the shape of the active site Substrate can no longer fit in the active site

pH There is a range of tolerance specific to each enzyme

Temperature There is a range of tolerance specific to each enzyme

How would you answer??

Describe the structure of an enzyme Describe the function of an enzyme Is this anabolism or catabolism?

1. What happens to an enzyme when it is denatured? It loses its shape B) It can catalyze more reactions C) Activation energy is raised D) Activation energy is lowered

2. Enzymes make reactions go _____ by ___the energy needed to start the reaction. slower; lowering B) faster; raising C) slower; raising D) faster; lowering

3. What is the optimal pH for the enzyme Salivary Amylase? B) 5 C) 11 D) 2 E) 7

Cornell Summary