Mrs. KooimanLa Serna High School

A. Forms of Energy Mechanical, Light and Chemical Energy

B. Energy can be absorbed or released by a chemical reaction

i. Chemical bonds break between atoms and new bonds are formed, producing different substances.

ii. Chemical EquationsCO2 + H2O H2C2CO3

Reactants Products

C. Energy is needed to start a chemical reaction.

i. Examples: Match starts a campfire, Sparkplug starts an engine

i. The energy needed to start a chemical reaction is referred to as Activation

Energy .

No Enzyme

Enzyme

Substances that increase the speed of chemical reactions

and decrease (lower) activation energy.

(In Living Organisms)

Called a CATALYST when found outside of living organisms!!

A. Structurei. Tertiary (3rd) Level PROTEINS (made up of

amino acid chains)B. Importance

i. Help maintain HOMEOSTASIS (balance)ii. Without enzymes reactions wouldn’t occur

quickly enough to sustain life.C. Naming Enzymes

i. End with the suffix –aseii. Example – lactase – enzyme that breaks

down lactose sugars

D. Factors that affect enzyme activity

i. Certain chemical conditions can cause the amino acid chain (protein) to permanently change shape or become DENATURED.

The Factors that affect enzyme activity include:

1.Temperature (Increase or Decrease)2.pH (acids and basis)3.Ionic Conditions (positive or negative

charges)4.Substrate Concentration

**A change in ANY of these can lead to a decrease in enzyme activity, and can

DENATURE the protein**

i. Enzyme-Substrate Complex

The reactants of enzyme-catalyzed reactions are known as the substrate.

1. Enzyme binds to a specific substrate2. Enzyme and substrate interact at the

active site.3. Reaction is complete when products are

formed.4. Enzyme is free to start process again.5. Your body turn enzymes “on” and “off”

at specific times.

Step 1

Step 2

Step 3

Step 4