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The wording of the correct answer choice to the following question is confusing to me:
Na+K+ ATPase is found in epithelial cells that produce urine or other excretions that are hypertonic relative to tissues. Why?
a) To form a hypertonic solution, ions or molecules must be actively transported across their concentration gradients.
b) Cells similar to those found in the shark rectal gland occur in many other species that need to excrete salt (NaCl).
c) The sodium-potassium pump is directly responsible for moving sodium ions from blood of body tissues into the urine for salt excretion, against a concentration gradient.
d) They are usually located in the basolateral membrane of those epithelial cells, along with other channels and cotransporters.
The correct answer given is (a). The question is given in my bio book in relation to the kidney. I was thinking about the Na+K+ ATPase pumps in the proximal tubule of the nephron and their role in creating an ion gradient for reabsorption of nutrients and water back into the blood stream during filtration. The choice (a) is confusing to me because it seems to emphasize the formation of a hypertonic solution due to the sodium potassium pumps.
Am I thinking about this correctly?
Na+K+ ATPase is found in epithelial cells that produce urine or other excretions that are hypertonic relative to tissues. Why?
a) To form a hypertonic solution, ions or molecules must be actively transported across their concentration gradients.
b) Cells similar to those found in the shark rectal gland occur in many other species that need to excrete salt (NaCl).
c) The sodium-potassium pump is directly responsible for moving sodium ions from blood of body tissues into the urine for salt excretion, against a concentration gradient.
d) They are usually located in the basolateral membrane of those epithelial cells, along with other channels and cotransporters.
The correct answer given is (a). The question is given in my bio book in relation to the kidney. I was thinking about the Na+K+ ATPase pumps in the proximal tubule of the nephron and their role in creating an ion gradient for reabsorption of nutrients and water back into the blood stream during filtration. The choice (a) is confusing to me because it seems to emphasize the formation of a hypertonic solution due to the sodium potassium pumps.
Am I thinking about this correctly?