Enzymes

What Are Enzymes? Most enzymes are Proteins Act as Catalyst to accelerates a reaction Not permanently changed in the process

Enzymes Are specific for what they will catalyze Are Reusable End in –ase -Sucrase -Lactase -Maltase

Salivary Amylase Demo Starch Glucose

How do enzymes Work? Enzymes lower activation energy

A catalyst lowers activation energy. Catalysts are substances that speed up chemical reactions. decrease activation energy increase reaction rate

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

What Affects Enzyme Activity? Environmental Conditions - increased temperature, -salt concentration, -pH

Toothpickase Activity Directions: Time how long it takes you to break 10 toothpicks without looking. Then, ice your hands for a few minutes. Try breaking the 10 toothpicks again while timing yourself. Temperature Time to break 10 toothpicks (seconds) Room temperature toothpickase   Cold toothpickase How does temperature affect the time in which toothpicks are broken by toothpickase?

Acids, Bases and pH H2O  H+ + OH- One water molecule in 550 million naturally dissociates into a Hydrogen Ion (H+) and a Hydroxide Ion (OH-) Hydrogen Ion Hydroxide Ion Acid Base H2O  H+ + OH-

The pH Scale Indicates the concentration of H+ ions Ranges from 0 – 14 pH of 7 is neutral pH 0 up to 7 is acid … H+ pH above 7 – 14 is basic … OH- Each pH unit represents a factor of 10X change in concentration pH 3 is 10 x 10 x 10 (1,000) stronger than a pH of 6

high OH- concentration The pH Scale low OH- concentration high OH- concentration

Acids Strong Acids have a pH of 0-3 Produce lots of H+ ions

Bases Strong Bases have a pH of 11 to 14 Contain lots of OH- ions and fewer H+ ions