Physioex 1: Cell Transport Mechanism and Permeability Practice Test

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• Which statement is true about simple diffusion and concentration gradients?
• Which statement about filtration in the human body is true?
• What primarily determines which substances cross and how?
• If you increase glucose concentration on the same side of the membrane, what happens to the rate of facilitated diffusion, assuming carrier availability is not limiting?
• In isotonic saline, what happens to red blood cells?
• Saturable transport is a property of which type of membrane proteins?
• Name two general ways cells can move substances against gradients.
• What is the Na+/K+ pump and what is its typical ion movement?
• How does molecular size affect diffusion across a lipid bilayer?
• Which of the following statements about osmosis is true?
• If external solute concentration increases on one side and is nondiffusible, osmotic pressure on that side will
• If the Na+/K+ pump is inhibited, what immediate ionic changes would you expect?
• What provides the energy for Na+/K+-ATPase activity?
• What characterizes an isotonic extracellular solution relative to a cell?
• With a 200 MWCO membrane, which solutes would you expect to diffuse?
• What is membrane potential and what contributes to it?
• How would you expect diffusion rate to change if membrane thickness increases?
• The top beaker in the filtration setup corresponds to which vascular structure?
• Define an electrochemical gradient.
• Secondary active transport relies on what to move solutes against their gradient?
• Which statement best defines osmosis?
• Why is there no pressure change when certain solutes diffuse through pores?
• Which statement correctly distinguishes carrier-mediated transport from simple diffusion?
• Which pair best predicts how quickly a solute will diffuse through a pure lipid bilayer?
• Why do ions require channels or transporters to cross a lipid bilayer?
• How can you experimentally distinguish diffusion from carrier-mediated transport?
• In osmosis, water moves toward the side with higher solute concentration.
• Which process involves uptake of extracellular fluid and dissolved solutes in small vesicles?
• When a solute is highly polar and large, which transport mode is most plausible?
• Which variable, when the number of transporter proteins is fixed, increases the rate of facilitated diffusion of glucose?
• A transporter follows Michaelis-Menten kinetics with Km = 5 mM and Vmax = 100 units. If [S] = 5 mM, what fraction of Vmax is observed?
• Which term best describes the rapid uptake of large particles or fluids into a cell via vesicles?
• In facilitated diffusion, increasing the concentration of glucose on one side of the membrane is equivalent to what change in the concentration gradient?
• Why must cells expend energy to maintain ion gradients?
• When diffusion stops, the solution has reached
• Carrier-mediated transport exhibits a transport maximum due to finite carrier numbers. True or False?
• Which factor would not affect the rate of facilitated diffusion?
• Explain competitive inhibition in carrier-mediated transport.
• Which observation differentiates carrier-mediated transport from channel diffusion?
• In an isotonic solution, what is true about water movement and cell volume?
• In energy-depleted conditions, which transport processes are most affected?
• What happens to a cell placed in a hypotonic extracellular solution?
• Filtration is primarily dependent on which gradient?
• According to the material, which solutes will not pass through a 20 MWCO membrane?
• If membrane permeability to a given ion increases, what happens to the resting membrane potential?
• Increasing Na+Cl- concentration will increase the osmotic pressure.
• When a cell is placed in an isotonic solution, what happens to its volume?
• Diffusion across a lipid bilayer versus diffusion through an open ion channel primarily differs in which way?
• Which statement best defines diffusion?
• What would be the effect of blocking aquaporin channels on osmosis?
• What does saturation of membrane transport proteins imply about diffusion rate at high substrate concentrations?
• In a dialysis tubing diffusion assay, which type of molecule would be least likely to diffuse through the membrane?
• How does cholesterol content affect membrane permeability?
• Which statement best explains saturability in transport?
• What was observed when glucose and albumin diffused through a 200 MWCO membrane?
• What happens to a plant cell in distilled water and why?
• In a hypertonic solution, what happens to red blood cells?
• Which statement best describes diffusion's relationship to solute gradient?
• The Na+/K+ pump is classified as which type of transporter?
• What is the function of ion channels in membranes?
• Which statement best explains why tonicity may differ from osmolarity in solutions containing permeant solutes?
• How do primary and secondary active transport differ?
• Which diffuses faster, sodium or urea, and why?
• In a dialysis diffusion experiment, which solute properties most influence movement into the bag?
• How does channel gating influence ion diffusion?
• Which is an example of a primary active transporter?
• Examples of solutes that might require facilitated diffusion include all of the above: glucose, sodium, and potassium.
• What is plasmolysis?
• How would decreasing temperature affect Vmax and Km for a transporter?
• How would you define osmolarity, and how is it different from tonicity?
• Which solute property most strongly predicts rapid diffusion through a lipid bilayer by simple diffusion?
• Define the transport maximum (Tm) in carrier-mediated diffusion.
• How would a competitive inhibitor of a carrier protein affect facilitated diffusion?
• Which statement correctly contrasts simple diffusion with the Na+/K+ pump?
• What is a common reason for incomplete solute recovery in filtration experiments?
• Which statement best describes filtration?
• Secondary active transport moves a solute against its gradient using which mechanism?
• In a hypotonic solution, what happens to red blood cells?
• Which statement describes how tonicity relates to membrane permeability and osmolarity?
• Which solute had the slowest diffusion rate among urea, sodium, glucose, and albumin in this setup?
• Solutes that require transport across membranes are typically either too large to pass by diffusion or are lipid insoluble.
• In facilitated diffusion, when carrier proteins are saturated, what happens to the rate as solute concentration continues to rise?
• Which statement best defines secondary active transport?
• Why does increasing substrate concentration initially increase the transport rate in carrier-mediated diffusion?
• What would be the effect of ouabain on Na+/K+ pump activity and ion distribution?
• Why was there not 100% recovery of NaCl with any membrane?
• What variable most directly increases the rate of simple diffusion across a membrane?
• In a dialysis diffusion experiment, if glucose diffuses but starch does not, what does this indicate about the membrane?
• The filtrate is the liquid that passes through the filter. Which option correctly describes the filtrate?
• Name two variables that affect the rate of diffusion.
• In a diffusion experiment, if impermeant solutes are added outside the system, which best describes water movement?
• During filtration, the filtrate includes which components?
• Which statement best distinguishes active transport from diffusion processes?
• Which type of solution would cause a typical animal cell to swell?
• What type of transport does the Na+/K+ pump primarily demonstrate?
• If the molecular weight of urea is 60.07 g/mol, will urea diffuse through a 20 MWCO membrane?
• A polar molecule that is poorly soluble in lipids would most likely require which mechanism to cross the cell membrane?
• What experiment principle explains why some solutes diffuse into a dialysis bag while others do not?
• What does ion channel gating refer to?
• Why can a large, charged solute be transported across the membrane if it is not diffusing?
• Which molecule diffuses directly through the lipid bilayer without a transporter due to being nonpolar?
• What does dialysis tubing model in membrane transport experiments?
• Which is an example of secondary active transport?
• Which type of solution would cause red blood cells to crenate?
• Which organ is a major site of bodily filtration?
• What is facilitated diffusion?
• Molecules need a carrier protein to help them move across a cell membrane because
• Lipid insoluble solutes require what to cross membranes?
• If you double the concentration of a nondiffusible solute on one side of a membrane, the osmotic pressure will
• The sodium-potassium pump moves _____ sodium ions and ____ potassium ions simultaneously.
• What is the primary function of aquaporins in cellular membranes?
• The effect of increasing the concentration of sodium chloride from 9 mM to 18 mM in the left beaker is to
• What is the effect of increasing membrane surface area on diffusion rate?
• What is the difference between diffusion and filtration?
• Which of the following statements determines osmotic pressure?
• What is facilitated diffusion?
• Define osmosis.
• Which statement best describes how filtration rate relates to the driving pressure across a membrane?
• What is the difference between permeability and selectivity?
• Which statement describes carrier-mediated diffusion saturation?
• Which transport mechanisms do not require direct ATP use?
• What does saturation of carrier-mediated transport mean?
• Which energy source powers the Na+/K+ pump?
• How does increasing surface area to volume ratio affect diffusion into a cell?
• What happens to the resting membrane potential if extracellular potassium concentration increases?
• How does a mutation that reduces aquaporin expression affect cell water movement?
• What does dialysis tubing model illustrate about membrane permeability?
• Which statement about diffusion via ion channels is true?
• What is the significance of membrane protein distribution for transport?
• In carrier-mediated diffusion, what happens as solute concentration increases before saturation?
• What is the expected effect on diffusion rate when temperature increases?
• Which transporter is a classic example of primary active transport?
• Which statement about facilitated diffusion is true?
• Which factors influence the diffusion coefficient (D) of a solute?
• How does active transport differ from facilitated diffusion?
• Nondiffusible solutes contribute to osmotic pressure.
• If you increase the pore size of the filter, what happens to the filtration rate?
• Filtration is a process that
• If [S] = 25 mM, Km = 5 mM, Vmax = 100 units, what fraction of Vmax is observed?
• Which factor does not influence the diffusion coefficient D?
• If extracellular impermeant solute concentration is higher outside than inside, what happens to cell volume?
• Using the given data, what is the approximate molecular weight of albumin?
• Which statement best describes the selectivity of receptor-mediated endocytosis?
• In facilitated diffusion, what provides the selective pathway for solute movement?
• Which statement best describes the Na+/K+ pump?
• Increasing cholesterol content in a membrane typically results in what change to its mechanical properties and permeability?
• Define primary active transport.
• Why did urea not diffuse through the 20 MWCO membrane?
• What is the effect of ouabain on cells dependent on Na+/K+-ATPase?
• Which process exports materials from the cell by vesicle fusion with the plasma membrane?
• Which statement best describes carrier-mediated transport’s dependence on solute concentration?
• Which statement correctly describes transport maximum in carrier-mediated transport?
• Which term describes a solution with osmolarity equal to the cell interior?
• What effect does increasing the number of glucose carriers have on the transport rate?
• What role do aquaporin channels play in osmosis?
• Which statement about Na+ and Cl- in glucose transport in the simulation is true?
• Which condition yielded the fastest glucose transport rate in the experiment?
• An increase in driving pressure corresponds to which change in the body?
• Why do ions diffuse slowly across a pure lipid bilayer?
• What is the stoichiometry for Na+/K+ pump?
• What happens to a cell placed in an isotonic solution (e.g., 0.9% NaCl)?
• How is osmolarity defined?
• What is meant by permeability?
• What powers the Na+/K+ pump?
• How does increasing temperature affect the rate of diffusion across a membrane?
• Which membrane disallows passage of Na⁺Cl⁻?
• The sodium-potassium pump is classified as a(n)
• After filtration, the filtrate contains which components?
• What determines the direction of water movement in osmosis when cells are placed in solutions of differing tonicity?
• What is the primary role of carrier proteins in transport?
• What is crenation and when does it occur?
• How does temperature affect diffusion rate across a membrane?
• What is vesicular transport and what processes does it include?
• Which solute did not pass through any membrane?
• Which statement best describes the relationship between carrier availability and diffusion rate for glucose?
• What does the term 'saturation' mean in facilitated diffusion?
• Which statement describes facilitated diffusion?
• What is the Na+/K+-ATPase and why is it important?
• What comprises an electrochemical gradient?
• How does a carrier protein exhibit substrate specificity?
• What term describes shrinking due to water loss in a hypertonic solution?
• Which statement differentiates phagocytosis from pinocytosis?
• What does MWCO stand for in membrane diffusion studies?
• What effect does adding Na+Cl- have on the glucose transport rate?
• Which ions are most affected inside the cell when the Na+/K+ pump is inhibited by ouabain?
• An increase in blood pressure would probably initially __________ filtration in the kidneys.
• Which solutes will diffuse through a 200 MWCO membrane?
• Per cycle, with the 3 Na+ out and 2 K+ in, what is the net movement of positive charge across the membrane?
• Why was equilibrium not reached in the diffusion experiment?
• In diffusion versus osmosis, which statement correctly describes what moves during each process?
• What is the hallmark of a saturable transport process?
• How does increasing glucose concentration from 2 mM to 8 mM affect the glucose transport rate?
• If solute concentrations are equal on both sides of a membrane, there is no net movement of water.
• Which statement best describes membrane selectivity?
• The movement of sodium and potassium maintained by the Na+-K+ pump
• If a solute is larger than the pore size, what is likely to happen during filtration?
• The Na+/K+ pump belongs to which class of enzymes?
• Why diffusion is inefficient for highly polar, large solutes?
• What happens to a cell in a hypertonic extracellular solution?
• Which solutes diffuse most readily across a pure lipid bilayer?
• Explain one key similarity and one key difference between facilitated diffusion and simple diffusion.
• Which statement about adding Na+Cl- to a solution is true regarding osmotic pressure?
• The rate of glucose transport increased when more glucose carriers were present. What is the best explanation for this?
• What is receptor-mediated endocytosis?
• Which ions are moved by the Na+/K+ pump and in which directions?
• If the extracellular solution has a higher impermeant solute concentration than the cell interior, what is the net effect on cell volume?
• A hypotonic solution causes the cell to swell.
• When a solute is able to diffuse through a membrane, an equilibrium is reached.
• In a hypotonic solution, which term best describes the solution relative to the cell?
• What will happen to the filtration rate if you increase the driving pressure?
• What is the key difference between tonicity and osmolarity?
• How is net flux defined?
• How do channels differ from carriers in facilitated diffusion?
• In membrane experiments, dialysis tubing is used to model membranes that are selective based on what properties?
• There is no net movement of water because the solute concentrations are the same.
• Would albumin diffuse through a 200 MWCO membrane based on its approximate molecular weight?
• Which statement about the diffusion rates of sodium and urea is true?
• Why do some solutes require transporter proteins to cross membranes?
• Which statement best describes passive transport?
• Which statement about saturability of transport mechanisms is true?
• Which statement best describes diffusion through MWCO membranes, given the context of the material?
• Why are carrier proteins often described as saturable?
• How would you determine experimentally if a transport process is saturable?
• In a Na+-glucose cotransport system, what happens if extracellular Na+ is removed?
• In a hypotonic solution, the net movement of water is into the cell.
• Which statement about osmosis is most accurate?
• In diffusion, does increasing solute concentration always increase the diffusion rate?
• Why can glucose cross a cell membrane only with a transporter while oxygen diffuses directly?
• Why might a large solute fail to diffuse into a dialysis bag?
• Which is an example of secondary active transport?
• Why were none of the solutes present in the filtrate?
• In a hypertonic solution, water moves out of the cell.
• Place the following solutes in order from smallest to largest molecular weight: glucose, sodium chloride, albumin, urea.
• Phagocytosis is a form of endocytosis that ingests what type of material?
• Which transport is most affected by a toxin that blocks transporter proteins?
• Which proteins primarily confer high water permeability to cell membranes?
• How do charged solutes typically cross membranes in physiological contexts?
• Doubling the concentration of a nondiffusible solute on one side of a membrane will affect osmotic pressure by
• During Na+/K+-ATPase activity, how many Na+ are pumped out and how many K+ pumped in per ATP?
• Which statement is true about osmosis?