2.5: Enzymes

Key Vocabulary

Prior learning and retrieval practice

A1: Methods of production of lactose-free milk and its advantages.

U5: Immobilized enzymes are widely used in industry.

• • Why produce lactose free milk?

  • How do we produce lactose free milk?

NoS: Experimental design—accurate, quantitative measurements in enzyme experiments require replicates to ensure reliability. (3.2)

S1: Design of experiments to test the effect of temperature, pH and substrate concentration on the activity of enzymes.

S2: Experimental investigation of a factor affecting enzyme activity. (Practical 3)

Adapt the methodology in the article below to design and carry out on investigation into a factor influencing enzyme activity

Guidance:

• Lactase can be immobilized in alginate beads and experiments can then be carried out in which the lactose in milk is hydrolysed.

Essential idea: Enzymes control the metabolism of the cell.

U1: Enzymes have an active site to which specific substrates bind.

U2: Enzyme catalysis involves molecular motion and the collision of substrates with the active site.

U3: Temperature, pH and substrate concentration affect the rate of activity of enzymes.

U4: Enzymes can be denatured.

Explain the lock and key mechanism of enzyme action. 

Sketch graphs to show how enzyme activity is affected by pH, temperature and substrate concentration

Guidance:

• Students should be able to sketch graphs to show the expected effects of temperature, pH and substrate concentration on the activity of enzymes. They should be able to explain the patterns or trends apparent in these graphs.