(b) The GLUT system is highly selective for glucose. It also speeds up the rate of glucosetransport across the membrane by as much as 100-fold when compared to the passive diffusionof glucose across a bilayer in the absence of any transport system. While impressive, this rate oftransport is much slower than purely diffusion limited rate of movement (ie. the fastest amolecule can move by diffusion). Given this fact, on the blank plot below draw the expectedrelationship between the rate of GLUT-mediated transport and increasing [glucose]? Use thespace below the graph to explain your answer.fastTransport Rateslowlow[glucose]high(c) Next, use a dashed line on the same plot above to draw the shape of the curve when theamount of GLUT transporters in the membrane is cut in half. Briefly explain your answer in thespace provided below the graph.

The Glucode transporter (GLUT) is involved in the facilitated diffusion of glucose across the cell…

Answered: (b) The GLUT system is highly selective…

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

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter7: The Peripheral Nervous System: Efferent Division

Section: Chapter Questions

Problem 1SQE

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Name the three classes of membrane transport proteins. Explain which one or ones of these classes is able to move glucose and which can move bicarbonate (HCO3−) against an electrochemical gradient. In the case of bicarbonate, but not glucose, the ΔG of the transport process has two terms. What are these two terms, and why does the second not apply to glucose? Why are cotransporters often referred to as examples of secondary active transport?
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
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.
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?
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
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 mechanistic difference results in this large difference in transport rate? What contribution to free energy (ΔG) determines the direction of transport?
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Below find the structures for ibogaine and cocaine. Ibogaine and cocaine inhibit the dopamine active transporter (DAT). This transporter is a secondary active transporter, and depends on the primary active transporter Na+/K+ ATPase. Ibogaine had a Kι = 2 μM, and cocaine a Kι = 0.64 μM respectively. (a) Define secondary active transport. (b) Is ibogaine an effective treatment for cocaine based on DAT binding?

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