Trypsin, a peptidase that hydrolyzes polypeptides, functions in the small intestine at an optimum pH of 7.7 to 8.0. How is the rate of a trypsin-catalyzed reaction affected by each of the following conditions?
a. changing the pH to 3.0

Verified step by step guidance

1. Understand the role of trypsin: Trypsin is an enzyme that catalyzes the hydrolysis of polypeptides in the small intestine. Enzymes have an optimum pH range where they function most effectively, and for trypsin, this range is 7.7 to 8.0.
2. Recall the effect of pH on enzyme activity: Enzymes are sensitive to pH changes because pH affects the ionization of amino acid side chains in the active site. Significant deviations from the optimum pH can lead to denaturation or reduced activity.
3. Analyze the given condition: The problem states that the pH is changed to 3.0, which is highly acidic compared to trypsin's optimum pH range. This drastic change in pH can disrupt the enzyme's structure and active site functionality.
4. Predict the impact on the reaction rate: At pH 3.0, trypsin is likely to lose its catalytic efficiency due to denaturation or altered active site geometry, leading to a significant decrease in the rate of the trypsin-catalyzed reaction.
5. Conclude the reasoning: The rate of the trypsin-catalyzed reaction will be negatively affected because the enzyme is no longer operating within its optimal pH range, and its ability to bind substrates and catalyze reactions is compromised.

Key Concepts

Enzyme Activity and pH

Enzymes, including trypsin, have an optimal pH range in which they function most effectively. Deviations from this range can lead to denaturation or reduced activity, as the enzyme's structure and active site may be altered. For trypsin, which operates best at a pH of 7.7 to 8.0, a drop to pH 3.0 would significantly impair its catalytic ability.

Trypsin Function

Trypsin is a serine protease that specifically cleaves peptide bonds in proteins, facilitating digestion in the small intestine. It is secreted as an inactive precursor, trypsinogen, and activated by other enzymes. Understanding its role in protein digestion is crucial for analyzing how changes in conditions affect its activity.

Reaction Rate and Environmental Conditions

The rate of enzyme-catalyzed reactions is influenced by various environmental factors, including pH, temperature, and substrate concentration. Changes in these conditions can either enhance or inhibit the reaction rate. In the case of trypsin, lowering the pH to 3.0 would likely decrease the reaction rate due to unfavorable conditions for enzyme activity.