All about Enzymes

Objectives:

To define catalyst and describe how enzymes function as catalysts in living organisms

A substance that alters A substance that alters the rate of a chemical the rate of a chemical reaction without itself reaction without itself being changed or used being changed or used

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Catalyst

Enzymes – proteins that are catalysts in cells

1) speed up a reaction by lowering activation energy

2) allow reactions to take place at lower temperatures

3) Regulate Metabolism

MetabolismMetabolism CatabolismCatabolism -”breakdown” of large

molecules into smaller units to release energy. Example: Polysaccharide

Monosaccharide

AnabolismAnabolism - "building up" of molecules and materials (organs, tissues) by using energy. Example: Glucose Glycogen

AnabolismAnabolism + Catabolism = + Catabolism = MetabolismMetabolism

The SUMSUM of all chemical reactions!

substrate – The substance affected

by an enzyme.

active site – region on an enzyme that can bind with a specific substrate.

Ex. Lactase binds to Lactose

substrate

Ways in Which Enzymes Catalyze Chemical Reactions

Ways in Which Enzymes Catalyze Chemical Reactions

1) holding two substrates in posit ions in which they can react with each other

2) twisting a substrate molecule slightly so that a chemical bond is weakened and broken