To determine which hypothesis most likely explains the results at 60°C, let's carefully analyze the situation involving enzyme activity and temperature.
1. Understanding enzyme activity and temperature:
- Enzymes are biological catalysts that speed up chemical reactions in living organisms. They have an optimal temperature range where they function most efficiently.
- At temperatures lower than the optimal, the rate of enzyme activity decreases because molecules are moving more slowly, leading to fewer collisions between enzymes and substrates.
- At temperatures higher than the optimal, enzymes may denature, meaning they lose their specific 3D structure and can no longer bind to substrates effectively.
2. Analyzing the enzyme activity data:
- At the given temperatures (10°C, 20°C, 30°C, 40°C, 50°C, 60°C), the enzyme activity increases up to a certain point (likely around 30-40°C) and then starts to decrease. By the time we reach 60°C, the enzyme activity has significantly dropped, indicating a change in enzyme efficiency.
3. Examining the hypotheses:
- Hypothesis A: "There was not enough molecular movement for the enzyme to be effective at this temperature."
- At 60°C, molecular movement is quite rapid, so this hypothesis is unlikely because the temperature is already quite high and should promote molecular movement.
- Hypothesis B: "The enzyme is effective only at very high temperatures."
- If the enzyme were only effective at very high temperatures, we would expect it to work better as the temperature increases. However, the data shows a decrease in enzyme activity at 60°C, which contradicts this hypothesis.
- Hypothesis C: "The enzyme changed shape because of the high temperature."
- Enzymes are sensitive to temperature, and high temperatures can cause them to denature (change shape). A significant drop in enzyme activity at 60°C supports this hypothesis, as the enzyme likely lost its proper shape and function.
4. Conclusion:
- Based on the data and the nature of enzyme activity, the most likely explanation for the results at 60°C is that the enzyme denatured due to the high temperature. Denaturation leads to a loss of the enzyme's functional shape, which in turn decreases its activity.
Therefore, the correct hypothesis that most likely explains the results at 60°C is:
C. The enzyme changed shape because of the high temperature.
