Question

biology activity: investigating enzyme activity
date:
use the graph below to answer questions 1 - 3.

1. at what temperature does this enzyme work the fastest?
2. why does enzyme activity increase on the left side of the graph?
3. why does enzyme activity decrease on the right side of the graph?

Explanation:

Step1: Analyze the graph

The graph shows enzyme activity against temperature. The peak of the curve represents the maximum enzyme activity.

Step2: Determine the temperature at the peak

Looking at the x - axis (temperature) corresponding to the highest point of the enzyme activity curve.

Step3: Explain the left - side increase

As temperature increases from 0°C, the kinetic energy of the enzyme and substrate molecules increases. This leads to more frequent and effective collisions between the enzyme and substrate, increasing the rate of the enzyme - catalyzed reaction.

Step4: Explain the right - side decrease

At higher temperatures (above the optimal temperature), the enzyme (a protein) starts to denature. Denaturation changes the shape of the enzyme's active site. So, the substrate can no longer bind effectively to the enzyme, reducing the enzyme activity.

Answer:

1. The enzyme works the fastest at approximately 20°C (the temperature at the peak of the curve).
2. Enzyme activity increases on the left side of the graph because as temperature rises, the kinetic energy of enzyme and substrate molecules increases, leading to more frequent and effective collisions.
3. Enzyme activity decreases on the right side of the graph because at higher temperatures, the enzyme denatures (its shape changes, especially the active site), so the substrate can no longer bind effectively.