enzymes. what are enzymes? enzymes are proteins. an enzyme is a catalyst. they speed up reactions...

EnzymesEnzymes

What are Enzymes?What are Enzymes?

Enzymes are proteins.

An enzyme is a catalyst. They speed up reactions that take place in your body.

Enzymes are proteins.

An enzyme is a catalyst. They speed up reactions that take place in your body.

What are Enzymes?What are Enzymes? Enzymes are very

specific. Will only catalyze

one specific reaction. Usually named for

the reaction they catalyze.

They are reusable and not permanently changed.

Enzymes are very specific.

Will only catalyze one specific reaction.

Usually named for the reaction they catalyze.

They are reusable and not permanently changed.

How Do Enzymes Work?How Do Enzymes Work?

Catalysts work by lowering the activation energy (the energy needed to start a chemical reaction) of the reaction=huge effect on the time it takes a reaction to happen!

Catalysts work by lowering the activation energy (the energy needed to start a chemical reaction) of the reaction=huge effect on the time it takes a reaction to happen!

5

6

FreeEnergy

Progress of the reaction

Reactants

Products

Free energy of activationFree energy of activation

Without Enzyme

With Enzyme

Enzymes lower the activation energy!Enzymes lower the activation energy!

The Enzyme-Substrate Complex

The Enzyme-Substrate Complex

Substrate: The substance (reactant) an enzyme works on.

Substrate: The substance (reactant) an enzyme works on.

EnzymeSubstrateJoins

The Enzyme-Substrate Complex

The Enzyme-Substrate Complex

ACTIVE SITE: The part of the enzyme where the substrate binds to it.

ACTIVE SITE: The part of the enzyme where the substrate binds to it.

EnzymeSubstrate

Active Site

They fit together like puzzle pieces!

They fit together like puzzle pieces!

VideoVideo

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_enzymes_work.html

The Enzyme-Substrate Complex

The Enzyme-Substrate Complex

How does it work?1.Substrates come in close

physical contact at the active site.

2.Substrates bind together and are made into products.

3.The products are released and the cycle starts over.

How does it work?1.Substrates come in close

physical contact at the active site.

2.Substrates bind together and are made into products.

3.The products are released and the cycle starts over.

http://www.youtube.com/watch?v=CZD5xsOKres

How Enzymes are NamedHow Enzymes are Named All enzymes end in –ASE!! The enzyme often sounds like the

substrate it breaks down.

All enzymes end in –ASE!! The enzyme often sounds like the

substrate it breaks down.

SUBSTRATE ENZYME

Lactose

Maltose

Sucrose

Lipids

Cellulose

Polysaccharides Amylase

Sucrase

Maltase

Lactase

Cellulase

Lipase

Things that Regulate Enzymes

Things that Regulate Enzymes

Temperature High temperatures can change

the structure of it. pH

Extremely high or low pH values can make it not work.

Temperature High temperatures can change

the structure of it. pH

Extremely high or low pH values can make it not work.

Review-Write these on the back of your notes.

Review-Write these on the back of your notes.

1. Enzymes area. Lipidsb. Carbohydratesc. Proteinsd. Nucleic Acids

2. Which binds to the active site of an enzyme?a. waterb. productc. another enzymed. substrate

Review (cont.)Review (cont.)

3. An enzyme can only bind one reactant (substrate) at a time.a. Trueb. False

4. An enzyme speeds up a chemical reaction in the cell, but can only be used once.a. Trueb. False

Review (cont.)Review (cont.)

5. Which substrate would this enzyme work on?

Review (cont.)Review (cont.)

6. Catalystsa. slow down a reaction.b. make enzymes.c. speed up a reaction.d. are nucleic acids.

7. What’s another name for enzyme substrate complex?a. Fast and slowb. Lock and keyc. Reactant and product d. Apple and pear

Review (cont.)Review (cont.)

8. Label:

Active Site

Enzyme

Substrate

Review (cont.)Review (cont.)

9. What happens in a chemical reaction after the substrate binds to the enzyme at the active site? a. The formation of a new product.b. The formation of another enzyme.c. Nothing happens.d. The enzyme is damaged.