Salivary alpha-amylase initiates the digestion of starch in the mouth. Which of the following best describes why its activity ceases shortly after the food enters the stomach?
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Correct answer: The enzyme is denatured by the low pH of gastric juice
Salivary amylase has an optimal pH of approximately 6.7 to 7.0. Once the bolus mixes with highly acidic gastric juice (pH 1.0 to 3.0), the protein structure of the enzyme is denatured, rendering it inactive.
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