Which of the following enzymes functions at the lowest pH?
Trypsin
Pancreatic amylase
Pepsin
Salivary amylase
The Correct Answer is C
A. Trypsin functions in the small intestine, where the environment is slightly alkaline. Therefore, this enzyme does not function at a low pH.
B. Pancreatic amylase also functions in the small intestine, where the pH is neutral to slightly alkaline.
C. Pepsin functions in the stomach, where the environment is highly acidic (pH 1.5 to 2). Pepsin is the correct answer because it works optimally at this low pH.
D. Salivary amylase functions in the mouth, where the pH is neutral or slightly alkaline.
Free Nursing Test Bank
- Free Pharmacology Quiz 1
- Free Medical-Surgical Quiz 2
- Free Fundamentals Quiz 3
- Free Maternal-Newborn Quiz 4
- Free Anatomy and Physiology Quiz 5
- Free Obstetrics and Pediatrics Quiz 6
- Free Fluid and Electrolytes Quiz 7
- Free Community Health Quiz 8
- Free Promoting Health across the Lifespan Quiz 9
- Free Multidimensional Care Quiz 10
View Related questions
Correct Answer is A
Explanation
A. The bicarbonate, phosphate, and protein: The major chemical buffer systems in the body are the bicarbonate buffer system, the phosphate buffer system, and the protein buffer system. These buffers help maintain pH balance in the blood and other fluids.
B. The urinary and digestive: The urinary and digestive systems are involved in excretion and digestion, not buffering.
C. The bicarbonate, nucleic acids, and protein: Nucleic acids are not major buffering systems in the body; the bicarbonate, phosphate, and protein systems are the primary ones.
D. The urinary and respiratory systems play roles in regulating acid-base balance through excretion and gas exchange but are not chemical buffer systems themselves.
Correct Answer is D
Explanation
A. It increases both Na+ and K+ secretion: Aldosterone increases sodium (Na+) reabsorption and potassium (K+) secretion, but it does not increase the secretion of both ions.
B. It causes the urine to be more diluted. Aldosterone causes the urine to be more concentrated by increasing sodium reabsorption and potassium secretion.
C. It reduces Na+ reabsorption and K+ secretion. Aldosterone actually increases sodium reabsorption and potassium secretion, not reduces them.
D. It increases Na+ reabsorption and K+ secretion. Aldosterone promotes sodium reabsorption in the kidneys and increases potassium secretion, leading to more concentrated urine.