The Na+ /glucose symport transports glucose from the lumen of the smallintestine into cells lining the lumen. Transport of 1 glucose molecule isdirectly coupled to the transport of 1 Na+ ion into the cell. 1 Na+out + 1 glucoseout → 1 Na+in + 1 glucoseinAssume the following conditions at 37 °C: [Na+]in = 12 mM, [Na+]out =145 mM, [glucose]out = 28 μM, and Δψ = -72 mV (inside negative).(a) What is ΔG for transport of Na+ from outside to inside under theseconditions?(b) What is the upper limit for [glucose]in under these conditions?(c) Which of the two hypothetical symports shown below (A or B) wouldachieve the highest concentration of [glucose]in under the conditionsdescribed above? Briefly explain your choice. A: 1 Na+out + 2 glucoseout → 1 Na+in + 2 glucosein B: 2 Na+out + 1 glucoseout → 2 Na+in + 1 glucosein

The Na+ /glucose symport transports glucose from the lumen of the smallintestine into cells lining the lumen. Transport of 1 glucose molecule isdirectly coupled to the transport of 1 Na+ ion into the cell. 1 Na+out + 1 glucoseout → 1 Na+in + 1 glucoseinAssume the following conditions at 37 °C: [Na+]in = 12 mM, [Na+]out =145 mM, [glucose]out = 28 μM, and Δψ = -72 mV (inside negative).(a) What is ΔG for transport of Na+ from outside to inside under theseconditions?(b) What is the upper limit for [glucose]in under these conditions?(c) Which of the two hypothetical symports shown below (A or B) wouldachieve the highest concentration of [glucose]in under the conditionsdescribed above? Briefly explain your choice. A: 1 Na+out + 2 glucoseout → 1 Na+in + 2 glucosein B: 2 Na+out + 1 glucoseout → 2 Na+in + 1 glucosein

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter3: The Plasma Membrane And Membrane Potential

Section: Chapter Questions

Problem 2SQE: One of the important uses of the Nernst equation is in describing the flow of ions across plasma...

See similar textbooks

Similar questions

Intestinal epithelial cells pump glucose into the cell against its concentration gradient using the Na-glucose symporter. Recall that the Na* concentration is significantly higher outside the cell than inside the cell. The symporter couples the "downhill" transport of two Na* ions into the cell to the "uphill" transport of glucose into the cell. If the Nat concentration outside the cell ([Na lout) is 141 mM and that inside the cell ([Na* lin) is 19.0 mM, and the cell potential is -52.0 mV (inside negative), calculate the maximum energy available for pumping a mole of glucose into the cell. Assume the temperature is 37 °C. AGglac 9.63 Incorrect kJ mol What is the maximum ratio of [glucose), to [glucose)out that could theoretically be produced if the energy coupling were 100% efficient? O 2700 1.13 3.7 x 10- 7.90
Intestinal epithelial cells pump glucose into the cell against its concentration gradient using the Nat-glucose symporter. Recall that the Na+ concentration is significantly higher outside the cell than inside the cell. The symporter couples the "downhill" transport of two Na+ ions into the cell to the "uphill" transport of glucose into the cell. If the Na+ concentration outside the cell ([Na+]out) is 155 mM and that inside the cell ([Na+ lin) is 21.0 mM, and the cell potential is -52.0 mV (inside negative), calculate the maximum energy available for pumping a mole of glucose into the cell. Assume the temperature is 37 °C. AGgluc = kJ mol What is the maximum ratio of [glucose] in to [glucose]out that could theoretically be produced if the energy coupling were 100% efficient? O 2700 7.89 O 1.14 3.7 x 10-4
Intestinal epithelial cells pump glucose into the cell against its concentration gradient using the Na+– glucose symporter. Recall that the Na+ concentration is significantly higher outside the cell than inside the cell. The symporter couples the "downhill" transport of two Na+ ions into the cell to the "uphill" transport of glucose into the cell. If the Na+ concentration outside the cell ([Na+]out) is 163 mM and that inside the cell ([Na+]in) is 21.0 mM, and the cell potential is −54.0 mV (inside negative), calculate the maximum energy available for pumping a mole of glucose into the cell. Assume the temperature is 37 °C.
Intestinal epithelial cells pump glucose into the cell against its concentration gradient using the Na*-glucose symporter. Recall that the Na+ concentration is significantly higher outside the cell than inside the cell. The symporter couples the "downhill" transport of two Na+ ions into the cell to the "uphill" transport of glucose into the cell. If the Na+ concentration outside the cell ([Na* lout) is 147 mM and that inside the cell ([Na+]in) is 17.0 mM, and the cell potential is -54.0 mV (inside negative), calculate the maximum energy available for pumping a mole of glucose into the cell. Assume the temperature is 37 °C. AG gluc kJ mol What is the maximum ratio of [glucose]in to [glucose] out that could theoretically be produced if the energy coupling were 100% efficient? 1.13 2.3 × 10-4 8.36 4300
O Att Intestinal epithelial cells pump glucose into the cell against its concentration gradient using the Nat-glucose symporter. Recall that the Nat concentration is significantly higher outside the cell than inside the cell. The symporter couples the "downhill" transport of two Nat ions into the cell to the "uphill" transport of glucose into the cell. If the Nat concentration outside the cell ([Na lout) is 161 mM and that inside the cell ([Na* Jm) is 17.0 mM, and the cell potential is -50.0 mV (inside negative), calculate the maximum energy available for pumping a mole of glucose into the cell. Assume the temperature is 37 °C. What is the maximum ratio of (glucose] to [glucoselout 10.62 kJ AG gluc mol that could theoretically be produced if the energy Incorrect coupling were 100% efficient? O 1.13 8.24 3800 2.6 x 10 Incorrect
The Na+/glucose Cotransporter The active transport of glucose is mediated by the Na+/glucose cotransporter. This is a symporter; that is, both the sodium ion and the glucose molecule are passing through the membrane in the same direction: sodium DOWN its gradient of about 140 mM outside to 10 mM inside while glucose is going UP its gradient (0.005 mM -> 5 mM) T=37oC and Vm = -70 mV CALCULATE THE ΔGin for Na+ (show work) – and is this enough energy to move glucose in? Or do you need to move 2 Na+ in for each glucose co-transported in? Explain
Digoxin, a toxin derived from the foxglove (shown), can be used to treat heart disorders such as atrial fibrillation. Digoxin's mechanism of action is to inhibit the Na+/K+ ATPase. Which of the following is the most likely side effect of Digoxin treatment? O Failure to transport glucose into cells while fasting (not eating) O Failure to transport Ht into lysosomes using direct active transport O Failure to transport glucose into cells after a meal O Failure to secrete pancreatic digestive enzymes in response to eating
The antibiotic valinomycin is an ionophore that forms a specific complex with potassium ion. Because the complex is lipophilic and can diffuse into the membrane, valinomycin brings about the transport of K+ through the inner membrane. Valinomycin acts by decreasing the ∆ψ (membrane potential) component of the pmf, without a direct effect on the pH gradient. Another antibiotic, nigericin, acts as a K+ >H+ antiporter; itcarries H+ in one direction, coupled with the reverse transport of K+. Thus,nigericin dissipates the pH component of the pmf, with little effect on ∆c.Which antibiotic, nigericin or valinomycin, do you predict would have thegreater effect on oxidative phosphorylation when administered to respiring mitochondria? Assume the antibiotics are added to a suspension of mitochondria in equimolar amounts. Briefly explain your reasoning.
Number of glucose carrier proteins in membrane Glucose diffusion rate (mM/sec) 300 0.0015 500 0.0023 700 0.0031 900 0.0040 How does increasing the number of glucose carrier proteins affect glucose diffusion rate?
Estimate the flux (mg/cm2/s) by diffusion of estrogen (a steroid) through a lipid bilayer cell membrane when assuming the diffusion coefficient for estrogen across the lipid bilayer is 10^–6 cm2/s, and that the initial concentration of estrogen in the extracellular fluid is 1 ng/mL and 0 in the cytoplasm.
Uniporters and ion channels support facilitated transport across cellular membranes. Although both are examples of facilitated transport, the rates of ion movement via an ion channel are roughly 104 - to 105 -fold faster than the rates of molecule movement via a uniporter. What key mechanisticdifference results in this large difference in transport rate?What contribution to free energy (ΔG) determines the direction of transport?
K+ [Select] [Select] A Na+ Primary active transport is being shown by transporter [Select] which uses [Select] ATP [Select] B The transported molecules in this mechanism are being moved [Select] to move Glucose active transport is being shown by transporter [Select] which uses the gradient. Secondary to move against the gradient. When both the molecules move through a transporter in the same direction as in B, this type of transport is called antiport.