Enzymes & Your Body

Biological molecule: Protein

Enzymes

Are

Review Chemical Reactions

Changes one set of chemicals into another set of chemicals.

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Involve changes in the chemical bonds that join atoms in compounds

Chemical reactions take place in cells all the time.

Chemical Reactions

Example

Biological Catalysts Details

Catalyst - a substance which speeds up a chemical reaction, is changed by the reaction.

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1. less energy to start chemical reaction.

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• Reaction is faster.

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3. catalyst is unchanged at the end of the reaction.

Enzymes are Catalyst

• Enzymes are catalyst to over 4000 biochemical reactions!

Product

Chemical Reactions

Chemical reactions take place in cells all the time.

Enzyme

Catalase

Water + oxygen

Catalyst

The biological catalyst present in the cytoplasm of plant and animal cells that speeds up the breakdown of hydrogen peroxide is called CATALASE.

Catalase cannot speed up any other reaction. It is SPECIFIC to this reaction.

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Enzymes can only act as a catalyst for one type of reaction

? - Why would you need an enzyme that breaks down hydrogen peroxide?

Hydrogen Peroxide in the body

Activation Energy

Enzymes lower the activation energy needed to start a chemical reaction.

Activation Energy

Make more sense this way?

Enzymes are Reusable

• Enzymes are reusable molecules found in living things.

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http://en.wikipedia.org/wiki/File:GLO1_Homo_sapiens_small_fast.gif

Enzyme Form and Function

• Lock & key Model: The shape of an enzyme allows it to do a specific job much like a lock and key.

Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

Naming Enzymes

• Take the name of the substrate the enzyme works on and add the suffix -ase
• Example: Lactose → Lactase

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MOVIE

Induced Fit Model

• Enzymes can form to the shape of its substrate.

Denaturing Enzymes

• When an enzyme is denatured it is damaged.
• Denaturing changes the shape.
• Without the correct shape enzymes won’t function properly.
• HOW are enzymes denatured?

Enzyme Inhibitors

• Chemicals that prevent the enzyme from working.
• Inhibitors decrease the enzyme reaction rate.

Enzyme Inhibitors

Enzyme Activators

• Chemicals that help the enzyme work.
• Activators increase the enzyme reaction rate.

Enzymes are used all over your body!

Classifying Enzymes

• There are 4 major categories of macromolecules: carbohydrates, lipids, proteins, & nucleic acids

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• Most enzymes belong to the class of proteins.