Summary Enzymes Study Guide

Enzymes Study Guide | High School Biology


1. What Are Enzymes?
Enzymes are special proteins that act as biological catalysts. A catalyst is a substance that speeds up
chemical reactions without being used up in the process. In living organisms, enzymes help important
reactions happen fast enough to support life. Without enzymes, many chemical reactions in the body
would occur too slowly.



2. Why Enzymes Are Important
• They speed up chemical reactions in cells.

• They help break down food during digestion.

• They help build important molecules like DNA and proteins.

• They control many metabolic processes in the body.



3. How Enzymes Work
Enzymes work by binding to molecules called substrates. The area of the enzyme where the substrate
attaches is called the active site. When the substrate binds to the active site, the enzyme helps convert
the substrate into products.




4. The Lock and Key Model
The lock and key model explains how enzymes are very specific. The enzyme's active site (the lock)
only fits a certain substrate (the key). This ensures that enzymes only catalyze specific reactions.



5. Factors That Affect Enzyme Activity
Factor Effect on Enzymes