* not completed

. In the Fick equation, J measures

the total diffusion. correct incorrect

the rate of diffusion. correct incorrect

the net rate of diffusion. correct incorrect

concentration. correct incorrect

* not completed

. Which of the following is not a variable in the Fick equation?

Distance separating regions of high and low concentration correct incorrect

Concentration difference correct incorrect

Diffusion coefficient correct incorrect

Charge correct incorrect

* not completed

. According to the Fick equation, what happens to J when X (the distance between the two concentrations) is increased?

The net rate of diffusion decreases correct incorrect

The concentration increases correct incorrect

The net rate of diffusion increases correct incorrect

The diffusion coefficient increases correct incorrect

* not completed

. Boundary layers tend to

increase the net rate of diffusion. correct incorrect

decrease the net rate of diffusion. correct incorrect

affect permeability only. correct incorrect

increase the local rate of diffusion but not the net rate of diffusion. correct incorrect

* not completed

. Electrical charges on molecules _______ diffusion across a membrane.

play a large role in correct incorrect

play an insignificant role in correct incorrect

accelerate correct incorrect

inhibit correct incorrect

* not completed

. Which of the following is not a type of gated channel?

Voltage-gated correct incorrect

Phosphorylation-gated correct incorrect

Ion-gated correct incorrect

Ligand-gated correct incorrect

* not completed

. In a typical animal cell, K⁺ tends to leak

into the cell due to its electrical gradient. correct incorrect

into the cell due to its concentration gradient. correct incorrect

out of the cell due to its electrical gradient. correct incorrect

out of the cell due to its concentration gradient. correct incorrect

* not completed

. 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?

Na⁺ will diffuse to the left side of the membrane, causing a net positive charge on the right side. correct incorrect

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

Na⁺ will diffuse to the left side of the membrane, but there will be no separation of charges. correct incorrect

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

* not completed

. 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?

Na⁺ will diffuse to the left side of the membrane, causing a net positive charge on the right side. correct incorrect

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

Na⁺ will diffuse to the left side of the membrane and K⁺ will not diffuse; however, there will be no separation of charges. correct incorrect

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

* not completed

. Which statement about facilitated diffusion is true?

It always occurs in the direction of electrochemical equilibrium. correct incorrect

It is a form of active transport. correct incorrect

Energy is used by the proteins in the transport process. correct incorrect

Solutes transported by this mechanism move across membranes much more slowly than they would if they did not associate with transporter proteins. correct incorrect

* not completed

. The proton pump in the stomach is an example of a(n) _______ pump.

electroneutral correct incorrect

electrogenic correct incorrect

glucose-mediated correct incorrect

facilitated correct incorrect

* not completed

. Na⁺–K⁺-ATPase pumps _______ the cell while _______ the cell.

2 Na⁺ out of; pumping 3 K⁺ into correct incorrect

3 Na⁺ into; pumping 2 K⁺ out of correct incorrect

3 Na⁺ out of; pumping 2 K⁺ into correct incorrect

2 Na⁺ into; pumping 3 K⁺ out of correct incorrect

* not completed

. Which is the best description of the immediate process by which glucose is transported across the epithelial membrane of the small intestine?

Active transport using Na⁺ correct incorrect

Cotransport with K⁺ correct incorrect

Active transport using ATP correct incorrect

Cotransport with Na⁺ correct incorrect

* not completed

. According to the whole-epithelium view of the gill, how does Cl^– enter the gill membrane of a freshwater teleost fish?

Passive countertransport with HCO₃^– correct incorrect

Passive cotransport with Na⁺ correct incorrect

Active countertransport with HCO₃^– correct incorrect

Active cotransport with HCO₃^– correct incorrect

* not completed

. Energy is used by _______ when bringing glucose into the intestinal epithelial cell.

Na⁺–K⁺-ATPase correct incorrect

the Na⁺-glucose cotransporter correct incorrect

Na⁺–H⁺-ATPase correct incorrect

the K⁺-glucose cotransporter correct incorrect

* not completed

. Which of the following is not a probable method of modulating channel or transporter function?

The existence of multiple molecular forms of the same channel or transporter correct incorrect

Control of the tissue-level expression of channels or transporters by gene expression correct incorrect

Blocking or permanent disabling of channels or transporters by ligands correct incorrect

Insertion or removal of channels or transporters from the plasma membrane correct incorrect

* not completed

. The colligative properties of an aqueous solution are the properties that depend on the

concentration of non-ionic particles dissolved in solution. correct incorrect

number of dissolved entities per unit volume. correct incorrect

number of dissolved entities per unit volume as well as their chemical nature. correct incorrect

concentration of ions dissolved in solution. correct incorrect

* not completed

. A 5 mOsm solution behaves as if it has

5 Avogadro's number of independent dissolved entities per liter. correct incorrect

5 M of dissolved nonionic entities. correct incorrect

5 mM dissolved nonionic entities. correct incorrect

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

* not completed

. The passive transport of water across a membrane is called

osmotic pressure. correct incorrect

osmosis. correct incorrect

diffusion. correct incorrect

ultrafiltration. correct incorrect

* not completed

. The blood plasma of a freshwater teleost fish is _______ relative to the pond water in which it lives.

isotonic correct incorrect

isosmotic correct incorrect

hyposmotic correct incorrect

hyperosmotic correct incorrect