2025 S3/4 CCKS Enzymes

Front

What is the mode of action of enzymes?

Back

Substrates bind to enzymes at their active site, forming an enzyme-substrate complex. A chemical reaction happens at the active site, converting the substrate into products.

Front

How do temperature and pH affect enzyme activity?

Back

Temperature and pH can significantly influence the rate of enzyme-catalyzed reactions, with each enzyme having optimal conditions for activity.

Front

What factors can denature enzymes?

Back

Factors such as extreme temperature and extreme pH changes will denature enzymes.

Front

In the 'lock and key' hypothesis, what is the lock?

Back

The enzyme.

Front

What is enzyme specificity?

Back

Enzyme specificity refers to the ability of an enzyme to select and catalyze a specific substrate among many possible candidates.

Front

How does substrate concentration affect enzyme activity?

Back

As substrate concentration increases, the rate of enzyme activity typically increases until a maximum rate is reached, after which it levels off (reach a plateau).

Front

In the 'lock and key' hypothesis, what is the key?

Back

The substrate.

Front

What is formed after the substrate binds to the active site of the enzyme?

Back

enzyme-substrate complex

Front

Describe the action of an enzyme at low temperatures. (assume optimum temperature to be 40 deg)

Back

At low temperatures, there is low kinetic energy, so the formation of enzyme-substrate complex is slower, hence there rate of enzyme activity is low.

Front

What happens during denaturation?

Back

During denaturation, the enzyme loses its 3D shape. Hence, the active site of the enzyme is no longer specific and complementary to the shape of the substrate. This process is irreversible.