Which of the following statements are correct? P. Plasma membrane is highly impermeable to all charged molecules Q. All membrane transport proteins so far known, are transmembrane multipass proteins R. Ionophores operate by shielding the charge of the transported ion so that it can penetrate the hydrophobic interior of the lipid bilayer. S. Na+-K+ ATPase exchanges equal numbers of Na+ and K+ ions in each pumping cycle P and Q R and S P and S Q and R

Which of the following statements are correct? P. Plasma membrane is highly impermeable to all charged molecules Q. All membrane transport proteins so far known, are transmembrane multipass proteins R. Ionophores operate by shielding the charge of the transported ion so that it can penetrate the hydrophobic interior of the lipid bilayer. S. Na+-K+ ATPase exchanges equal numbers of Na+ and K+ ions in each pumping cycle P and Q R and S P and S Q and R

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 1TAHL: Which of the following methods of transport is being used to transfer the substance into the cell in...

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Assume that a membrane permeable to Na+ but not to Cl- separates two solutions. The concentration of sodium chloride on side 1 is higher than on side 2. Which of the following ionic movements would occur? a. Na+ would move until its concentration gradient is dissipated (until the concentration of Na+ on side 2 is the same as the concentration of Na+ on side 1). b. Cl- would move down its concentration gradient from side 1 to side 2. c. A membrane potential, negative on side 1, would develop. d. A membrane potential, positive on side 1, would develop. e. None of the preceding is correct.
How is active transport different from simple diffusion? Both active transport and simple diffusion transport molecules against the concentration gradient. In active transport, molecules are moved down the concentration gradient; on the B contrary, molecules to be transported in simple diffusion are moved against the concentration gradient. In active transport, molecules are transported with the aid of transport proteins; on the © other hand, molecules to be transported in simple diffusion do not need transport proteins. In active transport, molecules that are transported does not need metabolic energy; in contrast, molecules transported in simple diffusion need metabolic energy.
The diagram below shows a tank system consisting of 3 compartments (A, B and C) and 2 membranes (X and Y) set up to study osmolarity and tonicity. The membrane permeabilities are shown in the table. Compartment A is filled with a solution of 300 mM Sucrose. Compartment B is filled with a solution of 100 mM CaCl, Compartment C has a solution of 300 mM Urea. The volumes in each compartment are the same at the beginning of the experiment. A Membrane X Membrane Y P 0 NA X B Po 0 0 Purs 0 100 11 11 11 II II II 11 11 11 II II II Y 10000 10000
The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient (this is a hydrogen ion H+ gradient), established via breakdown of ATP for energy, across the membrane-more acidic outside the cell than inside the cell. Phosphate transport may best described as an example of F Ocotransport or secondary active transport O facilitated diffusion O active transport O passive diffusion O osmosis
The comparison of the simple diffusion, facilitated diffusion and active transport are shown in the table below: * Which comparisons are TRUE? Simple Diffusion Facilitated Diffusion Active Transport I Require ATP Does not require ATP Require ATP II Does not involve a Involve a transport Involve a transport transport protein protein protein From a region of higher III From a region of higher concentrațion of substance to a region of lower concentration of From a region of lower concentration of concentration of substance to a region of lower concentration of substance. substance to a region of higher concentration of substance. substance. O I and II only I and III only O Il and III only O I, Il and III
Select the correct statments regarding transport of molecules across the cell membrane. Non-mediated transport is susceptible to saturation of transporter/channel proteins. Channels and transporters need not use energy to transport solute down the concentration gradient. The Na+/K+ antiport takes advantage of electrochemical gradients to exchange Na+ and K+ ions across the cell membrane. Active transport via electrochemical gradients relies on the passive transport of one solute to transport a second solute against the concentration gradient. Describe the three main sources of membrane fluidity
In Chapters 11 & 12, the following examples of membrane transport proteins are given. Fill out the table with the correct answer for that particular transport protein. Type of transport protein (channel or carrier/transporter?) K* leak channel glucose transporter bacteriorhodopsin Na-K pump glucose-Na symport Na-H exchanger Performs active or passive transport? Energy source for movement of solute(s) or ion(s) Direction of movement of solute(s) or ion(s) with respect to the electrochemical gradient Na K* Na glucose Na H' Direction of movement of solute(s) or ion(s) with respect to the membrane crossed Na K₁ Na' glucose Na H' Is the protein a uniport, symport, antiport, or none of the above?
Which of the following is FALSE regarding membrane transport? O A cell can add proteins into its membrane through the process of exocytosis O lons like Na+ or K+ do not enter a cell via simple diffusion O Hydrophobic molecules usually enter a cell via protein channels O lon channels must be integral proteins
Match the transport mechanisms with their descriptions. (1) diffusion (2) facilitated diffusion (3) filtration (4) active transport (5) endocytosis (6) exocytosis A. the cell membrane engulfs a particle or substance, drawing it into the cell in a vesicleB. movement down the concentration gradient with a carrier protein, without energy inputC. movement down the concentration gradient without a carrier protein or energy inputD. a particle or substance leaves a cell in a vesicle that merges with the cell membraneE. movement against the concentration gradient with energy inputF. hydrostatic pressure forces substances through membranes
. channels in the plasma membraneopen or close in response to changes in theelectrical charge difference across themembrane
When the nerves deliver a signal to contract, Ca++ (calcium ions) rush into the cell. The calcium ion influx causes specialized fibers to contract. Afterward, calcium ions are pumped out of the cell by calcium ATPases. What transport type(s) is occuring?s antiporter only ion gated transport followed by active transport active transport only ion gated transport only active transport followed by ion gated transport
In facilitated diffusion and active transport, how do transport proteins affect the rate of movement of molecules across the phospholipid selectively permeable membrane? A Transport proteins decrease the rate of movement of molecules. B Transport proteins stop the rate of movement of molecules. © Transport proteins increase the rate of movement of molecules. Transport proteins ensures all molecules may pass the membrane simultaneously.