CHP 4 HUMAN ANATOMY 2

Osmosis occurs through aquaporins (T/F)

A

If there is a difference in osmolarity between a cell and its environment, water will move ________ its osmotic pressure gradient. A) between B) through C) across D) down E) up

E

If there is 0.2 M glucose along with 0.15 M NaCl in solution, what is the osmolarity of this solution? A) 2.15 Osm B) 350 mOsm C) 300 mOsm D) 2.30 Osm E) 500 mOsm

E

In epithelial transport, movement from the internal environment to the external environment is called ________, whereas movement from the external environment to the internal environment is called ________. A) secretion : absorption B) pinocytosis : exocytosis C) catch : release D) absorption : excretion E) excretion : ingestion

A

The rate at which molecules are actively transported across a membrane is determined by the rate of transport of individual pumps and the number of pumps in the membrane (T/F)

A

Large differences in water concentration are required to drive water across a membrane (T/F)

B

The potassium equilibrium potential is -94 mV. What does this mean? A) At -94 mV, the chemical force for potassium movement is zero. B) At -94 mV, the chemical force for potassium movement is opposed exactly by the electrical force. C) At -94 mV, the electrical force for potassium movement is zero. D) At the resting membrane potential of neurons, potassium is at equilibrium. E) At -94 mV, potassium movement is opposed exactly by sodium movement

B

A carrier is a transmembrane protein that moves molecules across the membrane through A) small gaps in the fluid portion of the membrane. B) a lipid-filled pore. C) conformational changes in its protein shape. D) a water-filled pore. E) opening its gate and allowing molecules through

C

Insulin triggers the insert of what protein into the cell membrane of its target cell? A) insulin-like growth factor 1 B) glucagon C) GLUT4 D) hexose-6-kinase E) insulin-like growth factor receptor

C

If a solution contains 0.1 M glucose along with 0.15 M NaCl, what is the osmolarity of this solution? A) 350 mOsm B) 0.4 M C) 0.25 M D) 400 mOsm E) 250 mOsm

D

If solution 1 (0.1 M glucose and 0.15 M NaCl) and solution 2 (0.4 M glucose) are separated by a membrane, then solution 1 is ________ relative to solution 2. A) hypo-osmotic B) hypotonic C) hypertonic D) iso-osmotic E) hyperosmotic

D

Which ion(s) have a net chemical force acting to move the ion(s) into the cell? (Assume a resting membrane potential (Vm) of -70mV.) A) X+, whose [ECF] is 120 mM and [ICF] is 30 mM B) A-, whose [ECF] is 100 mM and [ICF] is 100 mM C) B-, whose [ECF] is 140 mM and [ICF] is 30 mM D) both X+ and B- ions E) X+, A-, and B- ions

D

Which of the following transport mechanisms is passive? A) transport of sodium and potassium across the membrane by the Na+/K+ pump B) countertransport of hydrogen ions with sodium C) movement of calcium out of the cytosol D) cotransport of glucose with sodium E) movement of sodium through ion channels

E

At the resting membrane potential, leakage of sodium ions into the cell and potassium ions out of the cell is balanced by the action of the Na+/K+ pump (T/F)

A

A 150 mM solution of NaCl is isotonic (T/F)

A

A cell with normal tonicity is placed in a 200 mM NaCl solution. This solution is ________ and the cell will ________. A) hypertonic : shrink B) hypotonic : swell C) hypertonic : swell D) isotonic : not change size E) hypotonic : shrink

A

Both K+ and Na+ ions have a plus one charge, yet it is their relative concentrations that chiefly determine how negative the cell's membrane potential will be. (T/F)

A

All of the following solutes are found in higher concentration inside of the cell EXCEPT A) glucose B) potassium. C) phosphate. D) ATP. E) calcium

E

The diffusion rate is A) fastest at body temperature. B) the speed at which diffusion takes place. C) the amount of time necessary for diffusion to take place. D) the amount of material to diffuse through a membrane. E) the thickness of the membrane through which a material has to diffuse

B

Which of the following will NOT increase the net flux of an ion across a membrane? A) elevated permeability of the membrane B) reduced surface area C) increased concentration gradient across the membrane D) more channels for that ion in the membrane E) enhanced surface area

B

The process of diffusion involves the random movement of A) ions against their concentration gradient. B) charged particles across a membrane. C) individual molecules based on their size and weight. D) molecules that is inversely proportional to its concentration. E) individual molecules due to thermal motion

E

What effect does a cell's overall thickness have on its permeability? A) Only the cell's membrane thickness, not that of its cytoplasm, have an effect on its permeability. B) As the cell's thickness increases, its permeability increases. C) The larger a cell becomes, the greater its proportional surface area, which increases the cell's permeability. D)The cell's permeability is directly proportional to the thickness traversed. E) As the cell's thickness increases, its permeability decreases

E

A beaker with a membrane is separating two solutions, initially of equal volumes. The solution on side A is 100 mM KCl while the solution on side B is 150 mM sucrose. The membrane is not permeable to ions or carbohydrates. In what way will the water move? A) down its concentration gradient from side B to side A B) down its concentration gradient from side A to side B C) In osmosis, water moves against its concentration gradient. D) As sucrose dissociates, it creates more individual molecules in solution and is therefore the higher concentration gradient. E) There is no movement of water.

A

In facilitated diffusion, the carrier protein has equal affinity for the molecule being transported on both sides of the membrane (T/F)

A

Most of the time, the body is neutral with respect to its electrical charge due to the equal distribution of anions and cations within the body (T/F)

A

Pumps can move ions in either direction, as long as it is moving against that ion's electrochemical gradient (T/F)

A

The driving force for simple diffusion is moving down its electrochemical gradient (T/F)

A

The movement of a molecule is determined by its energy state, with that molecule moving from a higher to a lower energy state. (T/F)

A

The movement of water across a membrane is always a passive process (T/F)

A

Which ion(s) have a net electrical force acting to move the ion(s) into the cell? (Assume a resting membrane potential (Vm) of -70mV.) A) X+, whose [ECF] is 120 mM and [ICF] is 30 mM B) A-, whose [ECF] is 100 mM and [ICF] is 100 mM C) B-, whose [ECF] is 140 mM and [ICF] is 30 mM D) both X+ and B- ions E) X+, A-, and B- ions

A

If the membrane potential is equal to the equilibrium potential for an ion, individual ions will NOT move across the membrane in either direction (T/F)

B

In active transport, the transporter has equal affinity for the molecule being transported on both sides of the membrane (T/F)

B

In the presence of two or more ions, it is the sum of their concentration that determines the direction of movement of those ions across a membrane (T/F)

B

Ions can always move through the ion channels present in the plasma membrane as long as there is an electrochemical gradient to drive the movement (T/F)

B

Phagosomes are formed following receptor-mediated endocytosis (T/F)

B

Pumps can move ions in either direction, as long as it is moving against that ion's electrochemical gradient (T/F)

B

The total amount of anions and cations in the body to keep it electrically neutral is maintained by homeostasis (T/F)

B

In epithelial tissue, the cells are linked together by ________, which prevent paracellular movement from lumen to extracellular fluid. A) gap junctions B) desmosomes C) tight junctions D) hemidesmosomes E) aquaporins

C

Which ion(s) would have a positive equilibrium potential? (Assume a resting membrane potential (Vm) of -70mV.) A) X+, A-, and B- ions B) B-, whose [ECF] is 140 mM and [ICF] is 30 mM C) X+, whose [ECF] is 120 mM and [ICF] is 30 mM D) A-, whose [ECF] is 100 mM and [ICF] is 100 mM E) both X+ and B- ions

C

In epithelial tissue, the portion of the plasma membrane facing the lumen is called the ________ membrane. The portion of the plasma membrane facing the connective tissue/interstitial fluid is called the ________ membrane. A) epithelial : basement B) secretory : attachment C) luminal : interstitial D) apical : basolateral E) apical : basement

D

If a 300 mOsm cell (10 mOsm of which are from the membrane permeable molecule urea) is placed into 300 mOsm solution containing no urea, what will happen to the cell? A) burst B) increased turgor C) swell D)no change E) shrink (shrivel)

E

As an ion moves passively across a membrane into the cell, the progressive increase in concentration within the cell will A) decrease the net flux across the membrane. B) decrease the need for active transport to continue transporting. C) accelerate the rate of diffusion. D) increase the net flux across the membrane. E) cause a switch to facilitated diffusion

A

All of the following statements concerning severe hyperglycemia's effect on serum Na+ levels are true, EXCEPT A) as insulin is administered, serum Na+ levels will return to normal. B) administering a hypertonic saline would help compensate for the decreased Na+ levels. C) levels are measured as a concentration, so as water decreases, levels increase. D) the amount of Na+ is really unchanged since the water has only changed location and not left the body. E) the Na+ levels would appear decreased as the ICF water leaves for the hyperosmotic ECF

B

As a cell's metabolism increases, so does its O2 consumption, giving rise to what product at a ratio of 2:1? A) pyruvic acid B) H2O C) ATP D) lactic acid E) CO2

B

Which of the following can be used to determine an ion's equilibrium potential? A) Navier-Stokes equation B) intracellular voltmeter C) Nernst equation D) oscilloscope E) concentration of an ion only

C

Which of the following cells would have a greater electrical attraction for sodium ions to enter the cell? A) cell with membrane potential = -50 mV B) cell with membrane potential = 0 mV C) cell with membrane potential = -90 mV D)cell with membrane potential = +20 mV E)cell with membrane potential = -70 mV

C

The equilibrium potential for a cation is +120 mV. Which of the following statements is TRUE when a cell is at the resting membrane potential (-70 mV)? A) The chemical force is directed into the cell and the electrical force is directed out of the cell. B) Both the chemical and electrical forces are directed out of the cell. C) The chemical force is directed out of the cell and the electrical force is directed into the cell. D) Both the chemical and electrical forces are directed into the cell. E) There is insufficient information to answer this question.

D

The chemical force for which of the following ions is directed into the cell? A) potassium only B) calcium only C) sodium only D) both potassium and sodium E) both sodium and calcium

E

Why are primary active transporters many times called ATPases? A)They must first bind to an ATP molecule before binding any transported molecule. B) They often breakdown ATP to AMP and pyrophosphate (an ATPase activity). C) ATP is synthesized during the reverse reaction and is named for that ability. D) ATP is the universal currency to get work done in the cell. E) They act as enzymes to release energy from ATP

E

As the molecular weight of a molecule increases, its A) membrane permeability decreases. B) ability to form a charge decreases. C) rate of diffusion will also increase. D) concentration in a solution decreases. E)ability to dissolve in lipid will also increase

A

Based solely upon its electrical charge, the inside of a typical cell will tend to attract extracellular ________ to move inward. A) cations B) ions whose concentration gradient allows them C) uncharged ions D) proteins E) anions

A

Chloride has an equilibrium potential of -90 mV. What direction are the chemical and electrical forces acting on the anion at the resting membrane potential (-70 mV)? A) The chemical force is directed into the cell and the electrical force is directed out of the cell. B) Both the chemical and electrical forces are directed out of the cell. C) The chemical force is directed out of the cell and the electrical force is directed into the cell. D) Both the chemical and electrical forces are directed into the cell. E) There is insufficient information to answer this question.

A

Endocytosis is a form of active transport (requiring energy) to move vesicles A) filled with particles and/or fluids into the cell. B) filled with particles and/or fluids out of the cell. C) containing particles into and out of the cell, also known as phagocytosis. D) containing fluids into and out of the cell, also known as pinocytosis. E) containing proteins out of the cell, also known as secretion

A

Epithelial cells are polarized with different structures at either end of the cell. The portion of the membrane that faces the lumen is called the ________ membrane. A) apical B) basolateral C) transport D)abluminal E)basement

A

What is the primary role for the Na+/K+ pump? A) the maintenance of Na+ and K+ concentrations on either side of the membrane B) to create a polarized membrane in an excitable cell C) the maintenance of Na+ and K+ concentrations once inside the membrane D) to produce ATP while pumping Na+ and K+ against their concentration gradients E) to pump Na+ and K+ down their concentration gradients out of the cell

A

When molecules are passively transported across a membrane, the direction of their movement is dictated by the molecule's tendency to move A) from higher to lower energy. B) out of a cell. C) from lower to higher energy. D) into a cell. E) in both directions; there is no preference

A

Which of the following transport mechanisms requires energy? A) phagocytosis B) facilitated diffusion C) osmosis D) diffusion E) movement of ion through ion channels

A

Which the following descriptions would be an example of phagocytosis? A) bacteria that is engulfed by a white blood cell B) a macrophage imbibing its surrounding tissue fluid and nutrients C) the elimination of a phagolysosome's contents from a neutrophil D) choline's reabsorption by a neuron E)a low-density lipoprotein that becomes internalized by a hepatic cell

A

Which the following descriptions would be an example of receptor-mediated endocytosis? A) a low-density lipoprotein that becomes internalized by a hepatic cell B) acetylcholine released from a neuron C) the elimination of a phagolysosome's contents from a neutrophil D) a macrophage imbibing its surrounding tissue fluid and nutrients E) bacteria that is engulfed by a white blood cell

A

An anion is found in greater concentration inside the cell than outside. Which of the following statements BEST describes forces acting on the anion at the resting membrane potential (-70 mV)? A) The chemical force is directed into the cell and the electrical force is directed out of the cell. B) Both the chemical and electrical forces are directed out of the cell. C) The chemical force is directed out of the cell and the electrical force is directed into the cell. D) Both the chemical and electrical forces are directed into the cell. E) There is insufficient information to answer this question.

B

Comparing intracellular to extracellular fluid, the intracellular fluid has a ________ charge relative to the outside of a cell due to the presence of more ________ in that solution. A) negative : cations B) negative : anions C) neutral : cations D) positive : cations E) positive : anions

B

If a positively charged ion is more concentrated inside the cell, the electrical forces required to balance the chemical gradient would be directed ________. Thus, the equilibrium potential for this ion would be ________ charged. A) outward : neutrally B) inward : negatively C) outward : negatively D) outward : positively E) inward : positively

B

In general, the molecules that move through specific carrier proteins are determined by which of the following? A) conformational changes in the pore B) the unique fit to binding sites on the channel or carrier protein C)the molecule's lipid solubility D)a water-filled pore E) the size of a molecule

B

In secondary active transport with sodium, which of the following is FALSE? A) ATP is necessary to produce an electrochemical gradient for sodium ions across the cell membrane. B) The molecule being transported moves down its electrochemical gradient. C) Sodium binds to a carrier molecule, changing its binding properties for another molecule to be transported across the cell membrane. D) The molecule being transported into the cell may move in or out, depending on the carrier molecule. E) Sodium always moves into the cell

B

The sodium-proton exchanger is an example of a(n) A) primary active transporter. B) antiporter. C) cotransporter. D) passive transporter. E) symporter.

B

What transport process couples the movement of an ion against its electrochemical gradient to another ion that is moving down its electrochemical gradient that was established using cellular energy (ATP)? A) primary active transport B) secondary active transport C) tertiary passive transport D) primary passive transport E) secondary passive transport

B

Which of the following is NOT a determinant of the magnitude and direction of the equilibrium potential for an ion? A) concentration gradient B) lipid solubility of the ion C) charge of the ion D) valence of the ion

B

Which of the following pairs of characteristics is more likely to make a substance diffuse through the cell membrane? A) large, non-polar molecule B) small, non-polar molecule C) large, polar molecule D) large, amphipathic molecule E) small, polar molecule

B

All of the following solutes are found in higher concentration outside of the cell EXCEPT A) HCO3-. B) sodium. C) proteins. D) magnesium. E) chloride

C

During phagocytosis, the phagosome binds with a(n) ________ to form a(n) ________. A)bacteria : null cell B) ingested particle : digested particle C) lysosome : phagolysosome D) ribosome : hybrid phagosome E)Golgi apparatus : vacuole

C

If a cell's Na+/K+ pump worked in reverse and had more leak channels for Na+ than for K+, what would the ion concentrations of the cell look like? A) Intracellular Cl- would be increased, following Na+. B) Intracellular concentration of K+ would still be higher than Na+ because the body tries to maintain an extracellular concentration of Na+ at 145 mM. C) Although the body tries to maintain an extracellular concentration of Na+ at 145mM, the intracellular concentration of Na+ would still be higher. D) Intracellular anions would decrease in number. E) The cell would swell since water follows Na+ .

C

If a molecule crosses a membrane and is quickly removed from the area by the blood stream or some biological pathway, what effect does this have on its rate of diffusion? A) Diffusion rate will remain constant. B) Diffusion rate will not be affected. C) Diffusion rate will increase. D) Diffusion rate will decrease. E) Diffusion rate will progressively decrease until zero

C

In active transport, the affinity of the carrier protein for the molecule being transported is greater on which side of the membrane? A) always the side facing the intracellular fluid B) always the side facing the extracellular fluid C) on the side where the molecule is in lower concentration D) on the side where the molecule is in greater concentration E) Neither; it is equal on both sides of the membrane

C

Molecules tend to move spontaneously ________ their chemical gradient. A) through B) up C) down D) over E) around

C

The extent of ion movement through the ________ space between epithelial cells is determined by the extent of ________ coupling between neighboring epithelial cells. A)transcellular : desmosomal B)transcellular : tight junctional C) paracellular : tight junctional D) transcellular : gap junctional E) paracellular : gap junctional

C

Vesicles formed during phagocytosis or endocytosis often fuse with the membrane of which of the following organelles? A) mitochondria B) smooth endoplasmic reticulum C) lysosome D) rough endoplasmic reticulum E)peroxisome

C

Which of the following is found in greater concentration inside the cell than outside? A) chloride B) calcium C) potassium D) sodium E) water

C

Which the following descriptions would be an example of exocytosis? A) choline's reabsorption by a neuron B) a low-density lipoprotein that becomes internalized by a hepatic cell C) acetylcholine released from a neuron D) bacteria that is engulfed by a white blood cell E) a macrophage imbibing its surrounding tissue fluid and nutrients

C

A membrane permeable to water separates a chamber into two compartments: A and B. Compartment A contains a 10 mM solution of non-permeating solute, whereas compartment B contains a 40 mM solution of non-permeating solute. Which of the following statements is TRUE? A) Both water and solute will move from side B to A. B) Solute will move from side B to A, and water will move from side A to B. C) Solute will move from side A to B, and water will move from side B to A. D) Water will move from side A to B, but solute will not move. E) Water will move from side B to A, but solute will not move.

D

If the solutions on either side of the membrane have an unequal distribution of charged ions, with the inside having an excess of anions, then the inside of the cell would have to be A) more positive, relative to the outside of the cell. B) more highly charged than the outside of the cell. C) less negative, relative to the outside of the cell. D) more negative, relative to the outside of the cell. E) less highly charged than the outside of the cell

D

One way that membrane surface area is increased in absorptive cells is through increasing the ________ of the apical membrane. A) receptor number B) thickness C) number of protein channels D) folding E) number of protein carriers

D

The first step of the Na+/K+ pump's activity involves the binding of which of the following? A) 3 Na+ to their binding site on the outside of the cell B) 2 K+ to their binding site on the inside of the cell C) 2 K+ to their binding site on the outside of the cell D) 3 Na+ to their binding site on the inside of the cell E) 3 Na+ and 2 K+ to their respective binding sites

D

Which of the following molecules is LEAST likely to diffuse through the phospholipid bilayer of the plasma membrane? A) steroids B) water C) fatty acid D) oxygen E) disaccharide

E

The flow of water across a membrane down its concentration gradient is called A) osmosis. B) symporting. C) facilitated diffusion. D) antiporting. E) leaking.

A

An erythrocyte is placed in a hypotonic solution of 100 mOsm. What will happen to the cell? A) The cell swells to three times its original volume, Vf = 3Vo. B) The cell shrinks to one half its original volume, Vf = 1/2 Vo. C) The cell swells to twice its original volume, Vf = 2Vo. D) The cell volume increases by one third, Vf = 4/3 Vo. E) The cell volume remains unchanged.

A

If a cell becomes damaged and is temporarily unable to produce ATP, what is the likely outcome with respect to H2O? A) cellular swelling, as water follows Na+ into the cell B) dehydration, as water diffusion is a passive process C) no change in water movement, as K+ is exchanged equally for Na+ D) no change in water movement, as the anionic proteins lose their charge and can no longer create a membrane potential E) dehydration, as water must be pumped in through aquaporins

A

Most water molecules that cross the plasma membrane do so by A) diffusion through aquaporins. B) diffusion through the plasma membrane. C) diffusion through ion channels. D) active transport by ion channels. E) active transport by aquaporins

A

Of the gradients listed below, which is the MOST accurate description of the force that ultimately determines the movement of ions across the membrane? A) electrochemical gradient B) potential gradient C) chemical gradient D) electrical gradient E) concentration gradient

A

Secretory vesicles are a part of what transport mechanism? A) exocytosis B) phagocytosis C) osmosis D) pinocytosis E) receptor-mediated endocytosis

A

The electrochemical gradient is to diffusion as ________ is to active transport. A) ATP B)an ion channel C) glucose D) thermal energy E) entropy

A

The hydrolysis of ATP on the Na+/K+ pump results in A) a conformational change that exposes the Na+ binding site to the outside of the cell. B) a conformational change that exposes the Na+ binding site to the inside of the cell. C) a conformational change that exposes the K+ binding site to the inside of the cell. D) Na+ adhering to its binding site. E) a conformational change that exposes the K+ binding site to the outside of the cell

A

The movement of a number of molecules across the apical surface of the epithelial cell by secondary transporters is coupled to the ________ gradient that is maintained by the ________ on the basolateral surface of the epithelial cell. A) Na+:Na+ /K+ pump B) Na+:Na+ channel C) K+:K+ pump D) Ca2+:Na+/K+ pump E) K+:K+ channel

A

The unequal distribution of charge in solutions on either side of a membrane will lead to a ________ of charge across the membrane and a ________ of counter ions in a region close to the membrane. A) separation : clustering B) collection : restriction C) separation : restriction D) buildup : restriction E) collection : clustering

A

Which of the following solutions bathing a red blood cell would be considered isotonic? A) a solution containing 100 mM MgCl2 B) a solution containing 200 mOsm NaCl C) a solution containing 300 mM NaCl D) a solution containing 400 mOsm non-permeating solute E) a solution containing 150 mM glucose

A

In facilitated diffusion, a molecule is moved A) against its concentration gradient with the assistance of a protein carrier molecule, but no energy is required. B) down its concentration gradient with the assistance of a protein carrier molecule, and no energy is required. C) with its concentration gradient while Na is moved against its concentration gradient. D) against its concentration gradient with the assistance of a protein carrier molecule and requires energy. E) against its concentration gradient while Na is moved with its concentration gradient

B

The Na+/K+ pump transports in which directions and what amounts per molecule of ATP hydrolyzed? A) 3 sodium ions in and 3 potassium ions out per molecule of ATP hydrolyzed B) 3 sodium ions out and 2 potassium ions in per molecule of ATP hydrolyzed C) They are transported in a 3:2:1 ratio in opposite directions. D) They are transported in a 1:1 ratio in opposite directions per molecule of ATP hydrolyzed. E) They are transported in a 3:2:2 ratio

B

Which the following descriptions would be an example of pinocytosis? A) the elimination of a phagolysosome's contents from a neutrophil B) a macrophage drinking its surrounding tissue fluid and nutrients C) a low-density lipoprotein that becomes internalized by a hepatic cell D) bacteria that is engulfed by a white blood cell E) choline's reabsorption by a neuron

B

Molecules with a relatively high lipid solubility are capable of crossing the membrane A) only with the addition of energy. B) only through specific protein channels. C) directly through the lipid bilayer. D) through specific lipid channels. E) indirectly by moving across a carrier protein

C

Oxygen diffuses from blood into cells down its concentration gradient. As cells become more active and oxidative phosphorylation increases in the cell, which of the following occurs? A) The concentration gradient for oxygen increases and oxygen movement into the cell decreases. B) The concentration gradient for oxygen and its rate of movement into the cell do not change. C) The concentration gradient for oxygen increases and oxygen movement into the cell increases. D) The concentration gradient for oxygen decreases and oxygen movement into the cell decreases. E) The concentration gradient for oxygen decreases and oxygen movement into the cell increases.

C

The concentration of sodium is greater in the extracellular fluid compared to the intracellular fluid. If the membrane potential was equal to the equilibrium potential for sodium, then what would be the direction of the electrochemical force acting on sodium? A) inward B) outward C) equal in both directions D) varies by cell E) varies based on concentration of potassium in the intracellular and extracellular fluids

C

What is responsible for the unequal distribution of ions across a membrane, thereby causing a charge? A) the concentration of carrier proteins in the membrane B) the ability of permeable ions to pass through a membrane C) the concentration of impermeable charged molecules D) the concentration of ions seeking equilibrium with respect to their charge E) The semipermeable membrane

C

What is the meaning of carrier proteins and pumps becoming saturated? A) They have a hydrogen molecule at every possible carbon bond and are, therefore, a solid at room temperature. B) These transporters have become entirely depleted and can no longer transport without further ATP production. C) These transporters have reached a maximal net flux, beyond which further increases in concentration no longer affect their rate. D) Saturation kinetics (demonstrated graphically as a line curving upward as a function of concentration) indicates that transport will increase as concentrations increase. E) These transporters have reached the point where only an increase in the transported molecule will change the net flux

C

When a substance crossing the membrane is driven by diffusion, the net flux of that molecule can be described mathematically by A) the Navier-Stokes equation. B) the Goldman-Hodgkin-Katz equation. C) Fick's law. D) Einstein's equation. E) the Nernst equation.

C

When more than one ion species (i.e., Na+ and K+) is present on both sides of the membrane, the chemical driving force acting on Na+ will include A) all ions present. B) the most concentrated ion only. C) sodium only. D) all negatively charged ions. E) all positively charged ions

C

When white blood cells are called to an area of infection, not only is there phagocytosis taking place, but also exocytosis of undigested particles from the white blood cells into the interstitial space. What effect does this have on water in the surrounding cells and capillary plasma? A) These particles have no effect on tonicity, since their precursors were already in the body. B) Swelling of the nearby cells and plasma ensues due to the hypotonic nature of the area. C) It creates a hypertonic environment, drawing water from the surrounding cells and plasma. D) It dehydrates the area due to the increase in lysosomal waste products. E)Plasma water moves to the interstitium by osmosis and then into the adjacent cells

C

Which of the following is NOT true for all three of these transport mechanisms: facilitated diffusion, primary active transport, and secondary active transport? A) The transport mechanism requires a protein. B) Transport can be increased by increasing the number of transport molecules in the plasma membrane. C) The transport mechanism requires energy. D) The transport mechanism is specific for (a) particular solute(s). E) The transport mechanism has a limit to the total number of molecules that can be transported per unit of time

C

Which of the following solutions bathing a red blood cell would be considered hypotonic? A) a solution containing 100 mM MgCl2 B) a solution containing 300 mM NaCl C)a solution containing 200 mOsm NaCl D) a solution containing 300 mM NaHCO3 E) a solution containing 400 mOsm non-permeating solute

C

Which of the following statements about Ca2+ pumps is FALSE? A) It is a form of primary active transport. B) Calcium is actively transported from the cytosol into the extracellular fluid. C) Calcium is actively transported from an organelle into the cytosol. D) The pump is also an ATPase. E) It maintains low cytosolic calcium levels.

C

Which of the following statements about glucose cotransport with sodium is TRUE? A) Glucose moves into the cell while sodium moves out of the cell. B) Glucose moves out of the cell while sodium moves into the cell. C) Glucose and sodium both move into the cell. D) Glucose and sodium both move out of the cell. E) Sodium moves out of the cell, but the movement of glucose will vary based on the type of cell.

C

Which of the following transport mechanisms has no energy requirement? A) endocytosis B) secondary active transport C) osmosis through aquaporins D) active transport E) exocytosis

C

Which of the following would NOT increase the rate of simple diffusion across the phospholipid bilayer of the plasma membrane? A) smaller size B) greater concentration gradient C) greater number of protein carriers D) greater available surface area E) greater lipid solubility

C

If a positively charged ion is more concentrated outside the cell, the electrical forces required to balance the chemical gradient would be directed ________. Thus, the equilibrium potential for this ion would be ________ charged. A) outward : neutrally B) inward : positively C) inward : negatively D) outward : negatively E)outward : positively

E

Na+ is released from its binding site on the Na+/K+ pump as a result of the A) interaction of the Na+ and K+ binding sites. B) exposure of the Na+ binding site to the inside of the cell. C) enzyme on the inside of the cell which cleaves the Na+ from its binding site. D) conformational change decreasing the affinity of the Na+ binding site. E) binding of K+ to its binding site

D

The concentration of an anion inside a cell is 0.3%. The concentration of this anion outside the cell is 0.1%. How could the cell obtain more of this ion inside the cell? A)exocytosis B)passive transport C) osmosis D) active transport E) pinocytosis

D

The equilibrium potential describes the membrane potential where what two forces are balanced? A) density and magnetic B) electrical and permeability C) chemical and temperature D) chemical and electrical E) temperature and density

D

The equilibrium potential describes the membrane potential where what two forces are balanced? A) density and magnetic B) electrical and permeability C) chemical and temperature D) chemical and electrical E) temperature and density

D

The osmotic pressure of a solution is a(n) A) direct measure of its solute concentration. B) indication of its glucose concentration. C) indirect measure of its solvent concentration. D) indirect measure of its solute concentration. E) direct measure of its solvent concentration

D

Transporting a substance against its concentration gradient requires A) countertransport with another molecule against its concentration gradient. B) a transporter that is facilitated in its diffusion. C) cotransport with another molecule against its concentration gradient. D) a transporter that uses energy. E) a channel that is specific for that substance

D

Which of the following transport mechanisms requires energy? A) primary active transport only B) secondary active transport only C) facilitated diffusion only D) both primary and secondary active transport E) both primary active transport and facilitated diffusion

D

With pulmonary hypertension, the lung's capillary walls become thicker to compensate for the higher pressure. What does Fick's law suggest will happen to CO2 concentrations? A) CO2 levels in the cells will decrease. B) CO2 levels in the blood will remain the same. C) CO2 levels in the tissues will decrease. D) CO2 levels in the blood will increase. E) CO2 in the alveoli will increase

D

A cell is placed into a solution that has the same osmolarity. However, one of the solutes in the solution is able to move across the membrane (the cell does not contain this solute). After a period of time, the solution into which the cell was placed would become A) hyperosmotic. B) iso-osmotic. C) hypertonic. D) isotonic. E) hypotonic

E

During cotransport of glucose with sodium, sodium increases the affinity of the carrier molecule for glucose when the binding site is facing which side? A) Cotransport does not involve changes in affinity of the carrier molecule. B) Sodium decreases the affinity of the carrier for glucose; it does not increase affinity. C) the intracellular fluid D) Both sides are affected equally. E) the extracellular fluid

E

What effect does uncontrolled diabetes mellitus have on blood osmolarity? A) none B) It decreases it, causing a hypo-osmotic state compared to normal. C) It increases it, causing a hypo-osmotic state compared to normal. D) It decreases it, causing a hyperosmotic state compared to normal. E) It increases it, causing a hyperosmotic state compared to normal

E

What effect would increasing the extracellular concentration of have on the resting membrane potential (RMP)? A) The RMP would become more negative. B) Increasing extracellular will have no effect on the RMP because of the / pump. C) The effects are really seen on the generating potential. D) Increasing extracellular will have no effect on the RMP because it displaces . E) The RMP would become more positive (less negative).

E

When solute is actively transported across epithelium, what usually follows? A) water movement in the opposite direction B) passive transport of the solute in the opposite direction C) passive transport of solute in the same direction D) active transport of the solute in the opposite direction E) water movement in the same direction

E

When the Na+/K+ pump moves its bound molecules of Na+ to the outside of the membrane, it A) binds to ATP to release the energy required to power the return trip. B) pumps more K+ back into the cell than the amount of Na+ that just came out. C) immediately returns to the inside of the cell, ready to transport more Na+ back outside. D) releases the bound ATP to return to its normal confirmation. E) cannot return to the inside empty-handed, so it must bind two K+ first

E

Which condition exists when there are more solutes present in a solution? A) There is a greater pressure for water to leave. B) There is a greater concentration of water to leave that solution. C) There is a greater need for an active transporter. D) There is a lower thermal energy affecting diffusion. E) There is a lower concentration of water in that solution.

E

Which of the following is a reflection of the unequal distribution of positive and negative ions across the plasma membrane? A) chemical driving force B) electrochemical driving force C) extracellular potential D) chemical gradient E) membrane potential

E

White blood cells are an important component of our immune system. One thing they do is consume and destroy bacteria by extending their plasma membrane around the bacterium and bringing it inside the cell in a vesicle. By what process do they engulf the bacterium? A) receptor-mediated endocytosis B) pinocytosis C) transcytosis D) exocytosis E) phagocytosis

E