Lucy examines the graph she made after analysing her experiment, which has the shape shown below. Isoleucine uptake (mmol/L cells/min) Time (min) At the point at which the curve has levelled off: Select one: a. The isoleucine uniporter has become saturated with substrate b. Isoleucine has equilibrated across the cell membrane, and its rate of influx via the isoleucine uniporter is the same as its rate of efflux C. The isoleucine uniporter has equilibrated isoleucine across the cell membrane, and switches off (stops functioning) after having done so ○ d. All of the radiolabelled isoleucine added to the cells is now inside the cells, so no more can be transported in e. All of the potential explanations above are equally likely

Lucy examines the graph she made after analysing her experiment, which has the shape shown below. Isoleucine uptake (mmol/L cells/min) Time (min) At the point at which the curve has levelled off: Select one: a. The isoleucine uniporter has become saturated with substrate b. Isoleucine has equilibrated across the cell membrane, and its rate of influx via the isoleucine uniporter is the same as its rate of efflux C. The isoleucine uniporter has equilibrated isoleucine across the cell membrane, and switches off (stops functioning) after having done so ○ d. All of the radiolabelled isoleucine added to the cells is now inside the cells, so no more can be transported in e. All of the potential explanations above are equally likely

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...

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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
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
The following table shows experimental results of the glucose transport rate, mM/sec, following facilitated diffusion by glucose carrier proteins. (Recall: the starting conc. L represents glucose added to one side of the membrane; distilled water, omM of glucose was added to the other side of the membrane). The rate of glucose transport was 0.0031 mm/sec with 8mM of glucose (run number 4, highlighted); the rate decreased to 0.0017 mM/sec with 10mM of glucose (run 5, highlighted). Why was the rate of glucose transport slower when the concentration gradient was increased? Experiment Results Run Number Solute 1 1 2 2 3 33 4 4 5 6 6 Na Ch Glucose Na Ch Glucose Na Ch Glucose Nat Ch Glucose Na Ch Glucose Nat Cl Glucose Start Conc. L Start Conc. R (MM) (mM) 0.00 0.00 2.00 0.00 0.00 0.00 8.00 0.00 0.00 0.00 2.00 0.00 0.00 0.00 8.00 0.00 0.00 0.00 10.00 0.00 2.00 0.00 2.00 0.00 Carriers 500 500 500 500 700 700 700 700 100 100 700 700 Rate (mm/sec) 0.0000 0.0008 0.0000 0.0023 0.0000 0.0010…
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
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
Two to three drops of mouse blood samples were placed in three different vials containing 0.07 M NaCl,0.15 M NaCl, and 0.30 M NaCl. A drop from each of the three vials were obtained and put on a slide forobservation under HPO. The effects of the different osmotic concentrations on the cells are shown in figures in your worksheets. Label the cell membrane for each figure. Give a short description (size and cell shape) for each of the RBC samples on the space provided in your worksheet. Compare their appearances with RBCs in the blood smear. Use the following guide questions in providing descriptions for each item. Which preparation has cells that look similar as those in the blood smear? What does this indicate about the movement of water in the cells? In which solution do the cells appear differently from the normal RBCs? What part of the cell could have possibly controlled such movement of water? What is its property that allowed this movement?
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?
What transport rates for each condition would you expect if the experiment was repeated using 12µM [3H] serotonin? Add your estimate into the table above.
The contraction of cardiac muscle cells results from the increase in Ca?+ levels in the cytosol. For these cells to relax, an antiport removes Ca?+ from the cytosol for every Nat that is taken in. Digitalis is a drug that is used to make the heart contract more strongly. This drug partially inhibits the Na*-K* ATPase in the cardiac cells. Applying the concepts from membrane transport, answer the following: a. Propose an explanation for the drug's effect. b. What will likely happen if too much of the drug is taken in? Why do you say so?
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.
Ion transporters are “linked” together—not physi-cally, but as a consequence of their actions. For example,cells can raise their intracellular pH, when it becomes tooacidic, by exchanging external Na+ for internal H+, usinga Na+–H+ antiporter. The change in internal Na+ is thenredressed using the Na+-K+ pump.A. Can these two transporters, operating together,normalize both the H+ and the Na+ concentrations insidethe cell?B. Does the linked action of these two pumps causeimbalances in either the K+ concentration or the mem-brane potential? Why or why not?