The Na/K atpase in the Shark epithelial cells of the rectal gland? A. Pumps both
ID: 144517 • Letter: T
Question
The Na/K atpase in the Shark epithelial cells of the rectal gland?
A. Pumps both Na and K against their concentration gradient
B. Pumps Na against its concentration gradient but moves with its concentration gradient
C. Pumps K against its concentration gradient but Na moves with its concentration gradient
D. Pumps both Na and K down along their concentration gradiet
E. none of the above
2.
The Na/K/Cl in the shark epithelial cells of the rectal gland
A.Pumps both Na and Cl against their concentration gradient
B.Pumps Na against its concentration gradient but Cl moves with its concentration gradient
C.Pumps Cl against its concentration gradient but Na moves with its concentration gradient
D.Pumps both Na and Cl down along their concentration gradient
E.None of the above
3.
The Na/K atpase in the epithelial cells of the proximal tubule
A.Pumps both Na and K against their concentration gradient
B.Pumps Na against its concentration gradient but K moves with its concentration gradient
C.Pumps K against its concentration gradient but Na moves with its concentration gradient
D.Pumps both Na and K down along their concentration gradient
E.None of the above
4.
The Na/K/Cl in the shark epithelial cells of the rectal gland
A.Pumps both Na and K against their concentration gradient
B.Pumps Na against its concentration gradient but K moves with its concentration gradient
C.Pumps K against its concentration gradient but Na moves with its concentration gradient
D.Pumps both Na and K down along their concentration gradient
E.None of the above
I need help those 4 questions and an explanation would also be helpful. Thanks :)
Explanation / Answer
Na/K ATPase in the Shark epithelial cells of the rectal gland --salt would flow out of the lumen and into the extracellular fluids of the shark. The intracellular concentration of chloride in intact glands exceeds the level expected at electrochemical equilibrium, suggesting active transport of chloride into the cell. These features suggest a simple hypothesis for chloride secretion in which the uphill transport of chloride into the cytoplasm is coupled via a membrane carrier to the downhill movement of sodium along its electrochemical gradient. The latter is maintained by the Na-K-ATPase pump while chloride is extruded into the duct by electrical forces.
The Na/K/Cl in the shark epithelial cells of the rectal gland--
Net Cl- movement from the blood to the lumen involves entry into the epithelial cells with Na+ and K+, followed by active Na+ extrusion via the pump and passive K+ exit via a channel. Intracellular [Cl-] is raised above electrochemical equilibrium and exits into the lumen when the apical Cl- channel opens. Cl- secretion is followed by a passive para-cellular flow of Na+
The Na/K ATPase in the epithelial cells of the proximal tubule ---
In the descending loop of Henle, sodium is transported by the basolateral sodium-potassium pump. Sodium gets in the cell through symporter membrane proteins on the proximal tubule epithelium luminal part. Additionally, sodium can also get into this part via antiporter membrane proteins.
The Na/K/Cl in the shark epithelial cells of the rectal gland--
key features of rectal gland secretion
Cl- uptake step across the basolateral membrane, the stimulation of a barium-sensitive K+ efflux mechanism on the basolateral membrane that most likely acts to recycle K+, and the activation of a Cl- transport pathway on the apical membrane that serves as a Cl- exit pathway..