Introduction to Enzymes

Flashcards created from lecture notes on the topic of enzymes, covering definitions, hypotheses, and factors affecting enzyme activity.

What are enzymes?

Enzymes are catalysts that speed up the rate of a chemical reaction.

What suffix is commonly associated with enzymes?

The suffix ‘-ase’ is a good indicator of an enzyme, e.g., lipase acts on lipids.

What is the role of the active site in an enzyme?

The active site is where the enzyme and substrate meet.

What happens to enzymes above 40°C?

The active site changes shape, preventing the enzyme from binding to the substrate, resulting in denaturation.

What is the 'Lock and Key' hypothesis?

This hypothesis states that an enzyme’s shape determines its function and only a specific substrate will fit into the enzyme.

What is the 'Induced Fit' hypothesis?

This hypothesis states that the enzyme changes shape to fit the substrate, resulting in a better fit and lowered activation energy.

Name one factor that affects enzyme activity.

Temperature, pH, enzyme concentration, substrate concentration, or presence of inhibitors.

What is a competitive inhibitor?

A competitive inhibitor binds to the active site and prevents the real substrate from binding.

What is a non-competitive inhibitor?

Non-competitive inhibitors cause a permanent blockage of the active site by substances such as poisons.

How does substrate concentration affect enzyme activity?

As substrate concentration increases, the rate of reaction increases until all active sites are filled, reaching a plateau.