Enzymes and Temperature: The Heat Factor in Reaction Rates

Enzymes are like temperature-sensitive workers—they perform best under the right conditions and stop working when it gets too hot or too cold.

 

What Are Enzymes?

• Enzymes are biological catalysts made of proteins.
• They speed up chemical reactions without being changed themselves. However, their efficiency depends heavily on temperature.

 

 

How Does Temperature Affect Enzymes?

Low Temperatures:

• At low temperatures, enzymes work slowly because molecules move slower, resulting in fewer collisions between enzymes and substrates.

 

Optimum Temperature:

• Each enzyme has an ideal optimum temperature where it works the fastest.
• For enzymes in the human body, this is typically around 37°C (body temperature).

 

High Temperatures:

• When the temperature gets too high, enzymes become denatured.
• Denaturation changes the enzyme's shape by breaking the bonds that hold the enzyme together, so the substrate no longer fits into the active site.
• Once an enzyme has denatured it cannot revert back to its original shape as it is an irreversible process

 

 

Key Terms:

• Optimum Temperature: The temperature at which an enzyme works best.
• Denaturation: Permanent change in the enzyme's shape due to high heat, making it inactive.

 

Real-Life Examples of Temperature and Enzymes

In the Human Body:

• Enzymes like amylase (in saliva) and pepsin (in the stomach) work best at body temperature (around 37°C).

Cooking and Denaturation:

• Cooking food at high temperatures denatures proteins (enzymes), which is why raw meat changes texture when cooked.