1. Enzymes

2. Objectives Define enzymes
Describe the effect of changes in temperature an pH on enzyme activity

3. Catalyst: a substance that speeds up a chemical reaction and is not changed by the reaction
Scientists say enzymes speed up, or catalyze, roughly 4,000 reactions in the body.

4. Enzymes: proteins that function as biological catalysts
Changes the substrate
Into the product
Substrate

5. For example: enzymes break down sugars for digestion

6. Enzyme Properties All enzymes are proteins
Enzymes work best at a particular temp
Enzymes are made inactive by high temps
Enzymes work best at a particular pH
Enzymes are not ‘used up’ in reactions
Enzymes are specific

7. Effect of Temperature on Enzyme Activity
As temperature
____________,
enzyme activity
can _________.
However, very high
temperatures denature
enzymes, or cause
them to stop working.

8. What is pH? pH is a measure of acidity Water has a neutral pH of 7
A change in pH can disrupt an enzyme’s shape and structure causing it to unravel, or denature.

9. Effect of pH on Enzyme Activity

10. Enzymes are named for what they catalyze
Protease = breaks down Protein
Lipase = breaks down Lipids (fats)
Carbohydrase = breaks down carbohydrates
Maltase = breaks down Maltose
Sucrase = breaks down Sucrose
Amylase = breaks down Starch
What are the substrates and products?

11. Not All Enzymes Are Created Equal
Stomach enzymes work in a super acidic environment of pH 2.
A little way down the digestive tract, intestine enzymes need a pH of 8.