Predict the reactivity of trypsin at pH 14. Enzymes work best at their optimum pH and trypsin works best at pH round 8-9 pH so if it’s increased pH is up to 14, trypsin will not work at pH 14 and get denatured. C 5. What is the optimal temperature for the enzyme in graph C? Where does the enzyme in graph C most likely function? 6. Using graph C: a. Explain what happens when hypothermia sets in (when enzymes get too cold!) The enzymes do not work as fast or as well when the temperature is below freezing
The Correct Answer and Explanation is:
Here are the correct answers to the questions, based on the provided image and general biological principles.
Correct Answers
4. Predict the reactivity of trypsin at pH 14.
Trypsin’s reactivity at pH 14 will be virtually zero. The extremely alkaline environment will cause the enzyme to denature, permanently altering the shape of its active site and rendering it non-functional.
5. What is the optimal temperature for the enzyme in graph C? Where does the enzyme in graph C most likely function?
- Optimal Temperature: While the peak of Graph C is not fully visible, enzyme activity is rising towards a maximum. For an enzyme in a mammal, the optimal temperature is typically around 37°C to 40°C (98.6°F to 104°F).
- Location: An enzyme with this optimal temperature most likely functions inside a warm-blooded animal, such as a human, where body temperature is maintained in this range.
6. a. Explain what happens when hypothermia sets in (when enzymes get too cold!)
When enzymes get too cold, as in hypothermia, their rate of activity decreases significantly. The low temperature reduces the kinetic energy of both the enzyme and its substrate molecules. This means they move more slowly, leading to fewer collisions between them. Consequently, the overall rate of metabolic reactions slows down, which can be dangerous for the organism. This effect is typically reversible; if the temperature returns to the optimum, the enzyme will regain its normal function.
Explanation
Enzymes are highly specific biological catalysts, and their function is critically dependent on environmental conditions like pH and temperature. Each enzyme has an optimal range for these factors where it exhibits maximum activity.
For question 4, trypsin’s optimal environment is the slightly alkaline condition of the small intestine, around pH 8. Exposing it to a pH of 14, which is extremely basic, causes a drastic change. This extreme pH disrupts the delicate ionic and hydrogen bonds that maintain the enzyme’s specific three-dimensional protein structure. This unfolding process, called denaturation, permanently changes the shape of the enzyme’s active site. Once the active site is altered, the enzyme can no longer bind to its substrate, and its catalytic activity ceases completely.
For questions 5 and 6, temperature directly influences the rate of enzymatic reactions. As temperature rises from a low point, molecules gain kinetic energy and move faster, increasing the frequency of collisions between the enzyme and its substrate, thus speeding up the reaction. This continues until the optimal temperature is reached, which for many enzymes in the human body is around 37°C. This is the point of peak performance.
In the case of hypothermia (question 6a), the body’s temperature drops below this optimum. This causes a significant reduction in kinetic energy. The enzyme and substrate molecules move sluggishly, decreasing the rate of effective collisions and slowing down all essential metabolic reactions. Unlike extreme heat, which causes irreversible denaturation, cold temperatures simply reduce molecular motion. If the temperature is restored to the optimal level, the enzyme’s structure remains intact, and its normal activity will resume.
