Summary
Enzymes are biological catalysts made of proteins that speed up chemical reactions in the body without being consumed. They are essential for metabolic processes and work best at specific temperatures and pH levels. Enzymes can be intracellular, acting inside cells, or extracellular, acting outside cells. They function through a mechanism where substrates bind to their active sites, forming an enzyme-substrate complex, which then releases products. Enzymes can be denatured by high temperatures or extreme pH, losing their functionality permanently.
Exam Tips
Key Definitions to Remember
- Enzyme: A protein that acts as a biological catalyst to speed up chemical reactions.
- Active Site: The region on an enzyme where the substrate binds.
- Denaturation: The process where an enzyme loses its shape and function due to high temperature or extreme pH.
Common Confusions
- Enzymes are not consumed in reactions; they can be reused.
- Denaturation is irreversible, unlike temporary inactivation at low temperatures.
Typical Exam Questions
- What is the role of enzymes in metabolism? Enzymes speed up metabolic reactions by lowering the activation energy.
- How does temperature affect enzyme activity? Enzymes have an optimum temperature; too high or too low temperatures can reduce activity or denature the enzyme.
- What is the lock and key hypothesis? It explains how enzymes and substrates fit together specifically, like a key in a lock.
What Examiners Usually Test
- Understanding of enzyme structure and function.
- Effects of temperature and pH on enzyme activity.
- Application of the lock and key model to explain enzyme specificity.
