1.4 Properties of Enzymes

Warm up – Day 1

1. What determines a protein’s shape?2. Why do you think shape is important?

Toothpick-ase

• Today your hands will be enzymes.• You will see what can affect the activity of an

enzyme.• Read the background section and fill out the

Checkpoint.• Have me check it off, then you can get your

supplies.

Warm up – Day 2

• Get out your Key Terms sheet. Which terms did you have a hard time defining? Compare with your neighbors and try to complete the sheet.

• WRITE FOLLOWING 5 QUESTIONS IN YOUR LOGBOOK—LEAVE ENOUGH ROOM FOR YOUR ANSWERS!

1. What is the difference in a reaction with or without an enzyme?

2.Why can an enzyme help only one reaction?

3.How can an enzyme be used repeatedly in a reaction?

4.What happens to an enzyme when it is heated or placed in acid?

5.List 4 properties of enzymes

Enzyme Animations

http://lpscience.fatcow.com/jwanamaker/animations/Enzyme%20activity.html

Without an enzyme

With an enzyme-

The molecules can line up correctly and perform the reaction easily.

Enzymes are specific They have a certain shape that only fits one type of molecule.

How can an enzyme be reused repeatedly?

What happens when it is heated or placed in acid?

The shape of the enzyme changes and the molecules do not fit into the enzyme anymore.

4 Properties of Enzymes1) Enzymes speed up the rate of chemical

reactions

2) Enzymes are NOT used up in the chemical reaction

- Only small amounts are needed since they are recycled and reused

3) Enzymes are specific to one type of chemical reaction

– Only lactose fits inside lactase

4) Enzymes are denatured (stop working because of shape change) when they are heated or placed in acid.

Yummy Proteins

• JELL-O is made of gelatin (a protein)

• Gelatin comes from bones and cartilage.

• 600 million pounds of gelatin is made every year (not all for JELL-O)

Yummy Tropical Fruits

• Have protein-breaking enzyme called papain or bromelain.

• Used as meat tenderizer.`

JELL-O and fruit - Predictions

No fruit

Fresh pineapple

Cooked pineapple

Solid? yes _____

no _____

yes _____

no _____

yes _____

no _____

In your logbook, write down what you think will happen in each container of JELL-O. Solid or not?

JELL-O and fruit - Results

No fruit

Fresh pineapple

Cooked pineapple

Solid? yes _____

no _____

yes _____

no _____

yes _____

no _____

In your logbook, write down what you think will happen in each container of JELL-O. Solid or not?

Idea Journal

In the Lesson 1.4 box:

Draw a model of a fresh pineapple cell and a canned pineapple cell. Explain what causes the difference between the two.

Fresh Pineapple Cell

Cooked Pineapple Cell

Draw the cellsDraw the substrate (THINK: what

molecule did the enzyme break down in the Jell-O?)

Draw the enzyme in each cell – fresh and cooked

Be sure the active site of the enzyme matches the substrate!