객관식
The liver and pancreas add their secretions to the partially digested food produced in the stomach, in the __________ of the small intestine.
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39. Digestive System
Digestion
객관식
Pepsin is an enzyme produced in the stomach that attacks proteins to break them down into smaller peptide molecules. Which of the following statements about this enzyme is true?
A
The activity of pepsin will speed up in the small intestine because the pH becomes less acidic.
B
Pepsin will continue to work at the same rate as it moves through the intestines until all the protein is broken down.
C
Salivary amylase activates pepsin, converting it to a functioning form in the stomach.
D
Pepsin will cease to function in the small intestine as basic secretions from the pancreas neutralize the pH.
검증된 단계별 안내1
Understand the role of pepsin: Pepsin is a protease enzyme that breaks down proteins into peptides. It is active in the acidic environment of the stomach.
Consider the pH environment: Pepsin functions optimally at a low pH, typically around 1.5 to 2.5, which is the pH of the stomach. The small intestine has a higher pH due to bicarbonate secretions from the pancreas.
Evaluate enzyme activity in different pH levels: Enzymes have specific pH ranges where they are active. Pepsin's activity decreases as the pH becomes less acidic, such as in the small intestine.
Analyze the statement about salivary amylase: Salivary amylase is an enzyme that breaks down carbohydrates, not proteins, and does not activate pepsin.
Conclude based on enzyme specificity: Pepsin will cease to function in the small intestine because the environment becomes less acidic, which is not conducive to its activity.
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