CP Chapter 5

The molecular species that binds and unbinds to the Na+‒K+-ATPase, causing sodium and potassium to shuttle through it, is a. PO42‒ .b. ATP. c. Na+‒K+-ATPase. d. ADP.

.b. ATP

In the Fick diffusion equation, if the units of D are cm2∙ s‒1 which of the following best represents the units for J? a. Moles ∙ cm‒2∙ s‒1 b. M ∙ cm ∙ s c. Moles ∙ sec‒1 d. M ∙ cm2∙ s

a. Moles ∙ cm‒2∙ s‒1

Which ion is moving into the cell via diffusion and where is it located? a. Na+is diffusing into the cell at I. b. K+is diffusing into the cell at I. c. K+is diffusing into the cell at V. d. Na+is diffusing into the cell at V.

a. Na+is diffusing into the cell at I.

Which diagram in the figure shows a voltage-gated channel? a. I b. II c. III d. IV

a. I

Which letter in the figure represents glucose? a. I b. II c. III d. IV

a. I

Which of the diagrams in the figure represents passive diffusion? a. III b. III and IV c. I and II d. I, II, and IV

a. III

Which statement about facilitated diffusion is true? a. It always occurs in the direction of electrochemical equilibrium. b. It is a form of active transport. c. Energy is used by the proteins in the transport process. d. Solutes transported by this mechanism move across membranes much more slowly than they would if they did not associate with transporter proteins.

a. It always occurs in the direction of electrochemical equilibrium.

Energy is used by _______ when bringing glucose into the intestinal epithelial cell. a. Na+‒K+-ATPase b. the Na+-glucose cotransporter c. Na+‒H+-ATPase d. the K+-glucose cotransporter

a. Na+‒K+-ATPase

According to the Fick equation, what happens to J when X (the distance between the two concentrations) is increased? a. The net rate of diffusion decreases b. The concentration increases c. The net rate of diffusion increases d. The diffusion coefficient increases

a. The net rate of diffusion decreases

Which y-axis measurement would not be supported by the figure? a. Total glucose uptake b. Mass-specific metabolic rate c. Glucose uptake per unit surface area of small intestine d. Glucose uptake per gram of animal weight

a. Total glucose uptake

If a piston moved up because of water movement, could it be physically pushed back down to force water through the membrane? a. Yes, the physical pressure would oppose the osmotic pressure. b. No, solutes would oppose the physical pressure. d. Yes, and this would generate more charge on the membrane. e. Yes, but only if the membrane were permeable to the solute.

a. Yes, the physical pressure would oppose the osmotic pressure.

The osmotic pressure of a solution is _______ to the concentration of dissolved entities. a. approximately proportional b. specific c. exponentially related d. not related

a. approximately proportional

Outward diffusion of a substance from an animal cell increases the concentration of that substance around the outer surface of the cell. This surface is called the a. boundary layer. b. bulk solution of the cell. c. region of backup diffusion. d. low-concentration region.

a. boundary layer.

The number of dissolved entities per unit of volume defines a. colligative properties. b. osmotic pressure. c. osmolarity. d. ultrafiltration.

a. colligative properties.

The proton pump in the stomach is an example of a(n) _______ pump. a. electroneutral b. electrogenic c. glucose-mediated d. facilitated

a. electroneutral

When two solutions exchange water by osmosis, water always moves a. from the solution with the lower osmotic pressure to the one with the higher osmotic pressure. b. from the solution with the higher osmotic pressure to the one with the lower osmotic pressure. c. via facilitated diffusion. d. from the lowest water concentration to the highest water concentration.

a. from the solution with the lower osmotic pressure to the one with the higher osmotic pressure.

In the animal cell, the overall concentration effects on Na+ diffusion cause Na+ to_______ the cell. a. move into b. move out of c. remain inside d. remain outside of

a. move into

Electrical charges on molecules _______ diffusion across a membrane. a. play a large role in b. play an insignificant role in c. accelerate d. inhibit

a. play a large role in

Most marine invertebrates typically have internal fluids of a. 1 mOsm. b. 1 Osm. c. 10 Osm. d. 300 mOsm.

b. 1 Osm.

Which statement regarding channels and transporters is false? a. Multiple molecular forms of channel and transporter proteins are common. b. Channel and transporter proteins have rapid turnover on the plasma membrane. c. Channel and transporter proteins are subject to covalent and noncovalent modulation. d. Channel and transporter proteins can be inserted into or retrieved from the plasma membrane.

b. Channel and transporter proteins have rapid turnover on the plasma membrane.

Which substance is mostly likely being pumped at A? a. Na+ b. H+ c. K+ d. ATP

b. H+

In the study of glucose transport, which pair of numerals in the figure represents the same ion? a. I and II b. II and III c. III and I d. IV and II

b. II and III

Among the ions outside and inside a typical living cell, which ion is furthest from electrochemical equilibrium? a. Cl‒ b. Na+ c. K+ d. Mg2+

b. Na+

If the membrane shown in the beakers is permeable only to Na+ , and the beaker on the left represents the initial state, a. Na+ will diffuse to the left side of the membrane, causing a net positive charge on the right side of the membrane. b. Na+ will diffuse to the left side of the membrane, causing a net negative charge on the right side of the membrane. c. Na+ will diffuse to the left side of the membrane, but there will be no separation of charges. d. there will be no net movement of ions.

b. Na+ will diffuse to the left side of the membrane, causing a net negative charge on the right side of the membrane.

A membrane that is permeable to only Na+ separates two solutions. The initial solutions are a 1-M solution of K+ on the left side of the membrane and a 1-M solution of Na+on the right side. What will occur? a. Na+ will diffuse to the left side of the membrane, causing a net positive charge on the right side. b. Na+ will diffuse to the left side of the membrane, causing a net negative charge on the right side. c. Na+ will diffuse to the left side of the membrane, but there will be no separation of charges. d. The movement of Na+ will be balanced out by the movement of K+ ; therefore, there will be no net charge difference.

b. Na+ will diffuse to the left side of the membrane, causing a net negative charge on the right side.

According to the Fick diffusion equation, which letter represents permeability? a. J b. Permeability is integrated into D c. Permeability is integrated into C1 - C2 d. X

b. Permeability is integrated into D

How does glucose cross the basolateral membrane? a. Via cotransport with Na+ at A b. Via facilitated diffusion c. Via active transport at C d. Via simple diffusion

b. Via facilitated diffusion

Boundary layers tend to a. increase the net rate of diffusion. b. decrease the net rate of diffusion. c. affect permeability only. d. increase the local rate of diffusion but not the net rate of diffusion.

b. decrease the net rate of diffusion.

When X increases in the Fick diffusion equation, J a. also increases. b. decreases. c. remains the same. d. can increase or decrease.

b. decreases.

In the animal cell, the combined concentration and electrical effects on K+cause K+to_______ the cell. a. move into b. leak out of c. remain inside d. remain outside of

b. leak out of

The colligative properties of an aqueous solution are the properties that depend on the a. concentration of non-ionic particles dissolved in solution. b. number of dissolved entities per unit volume. c. number of dissolved entities per unit volume as well as their chemical nature. d. concentration of ions dissolved in solution.

b. number of dissolved entities per unit volume.

The passive transport of water across a membrane is called a. osmotic pressure. b. osmosis. c. diffusion. d. ultrafiltration.

b. osmosis.

If you were to drop a mammalian red blood cell into a 10 mOsm solution, the red cell would _______ in this _______ solution. a. shrivel; hyposmotic b. swell and burst; hyposmotic c. swell and burst; hyperosmotic d. shrivel; hyperosmotic

b. swell and burst; hyposmotic

In the figure, the areas far above and far below the membrane denote a. a boundary layer. b. the bulk solution of the cell and extracellular fluid. c. capacitance. d. a net negative charge.

b. the bulk solution of the cell and extracellular fluid.

Outward diffusion of a substance from an animal cell increases the concentration of that substance around the outer surface of the cell. If this process continues, a. the rate of diffusion will increase. b. the rate of diffusion will decrease. c. the rate of diffusion will remain the same. d. active transport will be initiated.

b. the rate of diffusion will decrease

Na+‒K+-ATPase pumps _______ the cell while _______ the cell. a. 2 Na+ out of; pumping 3 K+ into b. 3 Na+into; pumping 2 K+out of c. 3 Na+out of; pumping 2 K+into d. 2 Na+into; pumping 3 K+out of

c. 3 Na+out of; pumping 2 K+into

According to the whole-epithelium view of the gill, how does Cl‒ enter the gill membrane of a freshwater teleost fish? a. Passive countertransport with HCO3 b. Passive cotransport with Na+ c. Active countertransport with HCO3 d. Active cotransport with HCO3 ‒

c. Active countertransport with HCO3

What type of process is shown in the figure? a. Simple diffusion b. Facilitated diffusion c. Active transport d. Osmosis

c. Active transport

Which of the following is not a probable method of modulating channel or transporter function? a. The existence of multiple molecular forms of the same channel or transporter b. Control of the tissue-level expression of channels or transporters by gene expression c. Blocking or permanent disabling of channels or transporters by ligands d. Insertion or removal of channels or transporters from the plasma membrane

c. Blocking or permanent disabling of channels or transporters by ligands

Which of the following is not a type of gated channel? a. Voltage-gated b. Phosphorylation-gated c. Ion-gated d. Ligand-gated

c. Ion-gated

Which statement regarding osmosis is true? a. Water cannot be described in terms of concentration. b. Osmotic pressure is inversely proportional to temperature. c. Large concentration gradients across cell membranes can generate osmotic pressure. d. Osmosis applies only to the movement of salts.

c. Large concentration gradients across cell membranes can generate osmotic pressure.

Which statement regarding facilitated diffusion is false? a. Diffusion occurs in the direction of electrochemical equilibrium. b. Solutes move faster with the protein facilitators than they would without them. c. Protein facilitators change conformation with the help of ATP. d. Solutes bind reversibly to the protein facilitators.

c. Protein facilitators change conformation with the help of ATP.

Which measure is not affected by the colligative properties of an aqueous solution? a. Freezing point b. Boiling point c. Temperature d. Osmotic pressure

c. Temperature

If the diagram represents the starting condition, what will occur as the solutions achieve equilibrium? a. The left piston will move up. b. The solutes will move but the pistons will not. c. The right piston will move up. d. The solutes will move to the left.

c. The right piston will move up.

Which process is electrogenic? a. Glucose transport into the small intestine epithelium b. Acid production in the stomach c. The sodium‒potassium pump on a typical cell membrane d. Sodium uptake in the freshwater fish gill

c. The sodium‒potassium pump on a typical cell membrane

If the figure on the left represents the initial state and the membrane shown in the beakers is permeable only to Na+ , which manipulation would cause a net negative charge on the left side of the membrane once the system comes to equilibrium? a. Making the membrane permeable only to water b. Allowing the membrane to become permeable to K+ as well as to Na+ c. Tripling the amount of A2 and allowing the membrane to become permeable to A2 d. Tripling the amount of A1 and allowing the membrane to become permeable to A1

c. Tripling the amount of A2 and allowing the membrane to become permeable to A2

The process of _______ arises from the molecular agitation that exists in all systems above absolute zero and the tendency for such agitation to carry more molecules out of regions of relatively high concentration than into these regions. a. facilitated diffusion b. active transport c. diffusion d. osmosis

c. diffusion

If a change in the voltage of a cell membrane causes all the voltage-gated Na+ channels to open, the permeability of the cell membrane to Na+ has been a. inhibited. b. decreased. c. increased. d. unaffected.

c. increased.

The passive transport of water across a membrane is called a. facilitated diffusion. b. diffusion. c. osmosis. d. osmotic pressure.

c. osmosis.

In the Fick equation, J measures a. the total diffusion. b. the rate of diffusion. c. the net rate of diffusion. d. concentration.

c. the net rate of diffusion.

A 1-M solution of Na2SO4 has _______ a 1-M solution of glucose. a. one-third the osmolarity of b. twice the osmolarity of c. three times the osmolarity of d. the same osmolarity as

c. three times the osmolarity of

The piston on the left would move upward if the membrane were permeable to only_______ and the solution on the left was _______ and the solution on the right was_______. a. Na+; 1M Na+; 3 M Cl‒ b. Cl‒; 1 M Cl‒; 3 M Na+ c. water and Na+; 2 M Cl‒; 3 M Na+ d. Ca2+; 1 M Na+; 3 M Ca2+

c. water and Na+; 2 M Cl‒; 3 M Na+

A 5 mOsm solution behaves as if it has a. 5 Avogadro's number of independent dissolved entities per liter. b. 5 M of dissolved nonionic entities. c. 5 mM dissolved nonionic entities. d. 0.005 Avogadro's number of independent dissolved entities per liter.

d. 0.005 Avogadro's number of independent dissolved entities per liter.

On the cell membrane, the Na+ ‒ K+pump transports _______ in for every _______that it transports out. a. 3 Na+; 2 K+ b. 2 Na+; 3 K+ c. 3 K+; 2 Na+ d. 2 K+; 3 Na+

d. 2 K+; 3 Na+

Most terrestrial vertebrates typically have internal fluids of approximately a. 1 mOsm. b. 1 Osm. c. 10 Osm. d. 300 mOsm.

d. 300 mOsm.

A 1-osmolar solution has _______ dissolved entities per liter. a. 1 kg of b. 1 dalton of c. 1.0 × 1023 independent d. 6.022 × 1023 independent

d. 6.022 × 1023 independent

Which statement about the transport of glucose into the gut epithelial cell through the apical membrane is true? a. The glucose transporter on the apical membrane uses ATP-bond energy. b. Glucose diffuses through the apical membrane using its own concentration gradient; therefore, it does not use any energy. c. Na+ uses ATP-bond energy as it brings in glucose at the apical membrane. d. ATP-bond energy is used at the Na+‒K+pump in setting up the Na+ gradient.

d. ATP-bond energy is used at the Na+‒K+pump in setting up the Na+ gradient.

At which location(s) in the figure is K+ moving into or out of the cell? a. I b. II c. Both I and V d. Both II and V

d. Both II and V

In which diagram do the channels open and close based on chemical bonding? a. I b. II c. III d. Both III and IV

d. Both III and IV

Which of the following is not a variable in the Fick equation? a. Distance separating regions of high and low concentration b. Concentration difference c. Diffusion coefficient d. Charge

d. Charge

Which is the best description of the immediate process by which glucose is transported across the epithelial membrane of the small intestine? a. Active transport using Na+ b. Cotransport with K+ c. Active transport using ATP d. Cotransport with Na+

d. Cotransport with Na+

At what point in the figure is energy being used? a. I b. II c. III d. IV

d. IV

Which of the diagrams most accurately represents the mechanism for glucose transport at the epithelium? a. I b. II c. III d. IV

d. IV

Which of the following statements about ion transport in the typical freshwater fish gill is true? a. Na+and HCO3‒are transported into the blood plasma. b. Na+and Cl‒are transported into the water. c. H+ and K+are transported into the water. d. Na+and Cl‒ are transported into the blood plasma

d. Na+and Cl‒ are transported into the blood plasma

A membrane that is permeable to Na+and K+separates two solutions. The initial solutions are a 1-M solution of K+on the left side of the membrane and a 1 M solution of Na+on the right side. What will occur? a. Na+ will diffuse to the left side of the membrane, causing a net positive charge on the right side. b. Na+ will diffuse to the left side of the membrane, causing a net negative charge on the right side. c. Na+ will diffuse to the left side of the membrane and K+ will not diffuse; however, there will be no separation of charges. d. The movement of Na+ will be balanced out by the movement of K+ ; therefore, there will be no net charge difference.

d. The movement of Na+ will be balanced out by the movement of K+ ; therefore, there will be no net charge difference.

The blood plasma of a freshwater teleost fish is _______ relative to the pond water in which it lives. a. isotonic b. isosmotic c. hyposmotic d. hyperosmotic

d. hyperosmotic

A solution that has a concentration effect on diffusion that is equal but opposite to the electrical effect is said to be a. in a steady state. b. part of the Nernst equation. c. in isoelectric balance. d. in electrochemical equilibrium.

d. in electrochemical equilibrium.

In the intestine, glucose is brought into the cell membrane by a. simple diffusion. b. active transport. c. facilitated diffusion. d. osmosis.

d. osmosis.

In a typical animal cell, K+ tends to leak a. into the cell due to its electrical gradient. b. into the cell due to its concentration gradient. c. out of the cell due to its electrical gradient. d. out of the cell due to its concentration gradient.

d. out of the cell due to its concentration gradient.

In the animal cell, the overall electrical effects on Cl‒ diffusion cause Cl‒ to _______the cell. a. move into b. remain equal on both sides of c. remain inside d. remain outside of

d. remain outside of

If the beaker on the left represents the initial state and the membrane shown in the beakers is permeable to K+and Na+ a. Na+ will diffuse to the left side of the membrane, causing a net positive charge on the right side of the membrane. b. Na+ will diffuse to the left side of the membrane, causing a net negative charge on the right side of the membrane. c. there will be no net movement of ions. d. the movement of Na+ will be balanced by the movement of K+ ; therefore, there will be no net charge difference.

d. the movement of Na+ will be balanced by the movement of K+ ; therefore, there will be no net charge difference

A 1-M solution of serum albumin (66,000 daltons) has _______ a 1-M solution of urea (66 daltons). a. one-thousandth the osmolarity of b. twice the osmolarity of c. one thousand times the osmolarity of d. the same osmolarity as

d. the same osmolarity as