The optimum pH of pepsin is around:
Correct answer: C. 2
- A. 3
- B. 3.5
- C. 2
- D. 2.5
Explanation
The stomach contains gastric glands that secrete hydrochloric acid (HCl) along with pepsinogen, an inactive precursor of pepsin. When food enters the stomach, HCl is secreted and lowers the pH of the stomach contents. This acidic environment (pH around 2) is created by the HCl and provides the ideal conditions for pepsin activation. At this low pH, pepsinogen is converted into its active form, pepsin. Pepsin then carries out the breakdown of proteins into smaller peptides and amino acids, which can be further absorbed and utilized by the body. Therefore, option c is correct.
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About Factors Affecting Enzyme Action
Enzyme activity changes with temperature, pH, substrate concentration and enzyme concentration because these factors affect molecular collisions and the active site. Questions also examine optimum conditions, denaturation and inhibition, while distinguishing a fall in activity caused by unsuitable conditions from permanent enzyme damage.
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