Study Guides

Unit Summary

This unit explores the roles of sugars, amino acids, and fatty acids in the synthesis and breakdown of biological molecules. It covers enzyme action, transport in organisms, hypothesis development, and data interpretation. Emphasis is on planning experiments and presenting explanations.

Lesson Summary

You will learn to explain what an enzyme is and why the shape of an enzyme is important for how it works.

Key Notes

• Enzymes are proteins that act as catalysts, speeding up chemical reactions.
• Without enzymes, many reactions would happen too slowly to support life.
• Enzymes catalyse reactions essential to life, including digestion and reactions in photosynthesis and respiration.
• Each enzyme has a 3D shape with an active site that a specific substrate fits into.
• The lock and key model to explain enzyme-substrate interactions.

Vocabulary To Learn

• enzyme: A protein which acts as a biological catalyst.
• catalyst: A substance that speeds up the rate of a reaction without being used up.
• active site: The part of an enzyme where the substrate binds.
• substrate: The substance which is acted upon by the enzyme.
• model: Scientists use models as simpler representations of complex things and ideas.

Common Mistakes To Avoid

• That enzymes are used up in reactions, or that an enzyme can catalyse many different reactions.

3 Quick Questions (With Answers)

More Lessons In This Unit

• Biological molecules Study Guide
• Effects of substrate concentration and temperature on rate of enzyme activity Study Guide
• Explaining effects of substrate concentration and temperature on enzyme rate Study Guide
• Obtaining the elements needed to make biological molecules Study Guide
• Tests for biological molecules Study Guide
• The effect of pH on the rate of an enzyme reaction: data analysis Study Guide
• The effect of pH on the rate of an enzyme reaction: plan Study Guide
• The effect of pH on the rate of an enzyme reaction: practical Study Guide