Ch.5

What is the value for the resting membrane potential for most neurons? +30 mV -90 mV -70 mV

-70 mV

The resting membrane potential in most cells is approximately 0 mV. +70 mV. -35 mV. +35 mV. -70 mV.

-70 mV.

Facilitated diffusion and active transport differ in that ATP is necessary for active transport, but not for facilitated diffusion. facilitated diffusion uses a substrate to bind to a protein carrier, whereas active transport does not. facilitated diffusion moves water across the cell membrane, whereas active transport does not. potential energy is required for active transport but not for facilitated diffusion. facilitated diffusion uses cell membrane proteins to move substances, whereas active transport does not.

ATP is necessary for active transport, but not for facilitated diffusion.

The term cellular (metabolic) energy indicates any biological process requiring ATP. energy in any form. thermal energy. chemical energy. thermal energy and chemical energy.

ATP.

Gated channels for sodium ions may include chemical gates, which respond to ligands. mechanical gates, which respond to pressure. voltage gates, which respond to electrical signals. All of the answers are correct. None of the answers are correct.

All of the answers are correct.

Which molecules can move across the phospholipid bilayer by simple diffusion? steroids lipids and water water lipids All of the answers are correct.

All of the answers are correct.

What is the most important distinction between the membrane transporters known as channel proteins and those known as carrier proteins? Channel proteins do not require energy, whereas carrier proteins do require energy. Channel proteins transport only very small substances. Carrier proteins transport macromolecules. Channel proteins create water-filled passages for small substances that do not bind to the protein. Carrier proteins transport larger substances by binding to them. Channel proteins transport water-soluble substances. Carrier proteins transport water-insoluble substance.

Channel proteins create water-filled passages for small substances that do not bind to the protein. Carrier proteins transport larger substances by binding to them.

Which property of diffusion best explains why a circulatory system is needed in multicellular organisms? Diffusion is rapid over short distances but much slower over long distances. Diffusion rate is inversely related to molecule size. Diffusion can take place in an open system or across a partition that separates two systems. Molecules move from an area of higher concentration to an area of lower concentration.

Diffusion is rapid over short distances but much slower over long distances.

Where is most of the water in the body located? Intracellular fluid Lumens of the digestive and urinary tracts Interstitial fluid Plasma

Intracellular fluid

When you eat a large meal and your body absorbs a lot of glucose and that makes its way to the interstitial fluid before going into the cell. 100% of the glucose should be absorbed into the cell from the interstitial fluid. Why does nearly all of the glucose enter the cell, rather than only half of it? It is modified by the cell, so there is still more glucose on the outside of the cell than inside it. The cells make ATP so fast, they use up all the glucose as soon as it enters the cell. Insulin forces glucose into the cell against a concentration gradient. It is moved by active transport.

It is modified by the cell, so there is still more glucose on the outside of the cell than inside it.

Which statement about the resting membrane potential is TRUE? It is due in part to the presence of extracellular proteins. It is normally equal to zero volts. It results, in part, from the concentration gradients for Na+ and K+. The inside of the membrane is positively charged compared to the outside.

It results, in part, from the concentration gradients for Na+ and K+.

Which statement about the Na+/K+ pump is FALSE? Its activity requires energy input. It transports Na+ and K+ in a 1:1 ratio. It is present in neurons. It transports Na+ out of the cell and K+ into the cell.

It transports Na+ and K+ in a 1:1 ratio.

The membranes of neurons at rest are very permeable to _____ but only slightly permeable to _____. Na+; K+ Na+; Cl- K+; Na+ K+; Cl-

K+; Na+

Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel? Sodium-potassium ATPases Leak channels Ligand-gated channels Voltage-gated channels

Leak channels

The concentrations of which two ions are highest outside the cell. Na+ and A- (negatively charged proteins) K+ and Cl- K+ and A- (negatively charged proteins) Na+ and Cl-

Na+ and Cl-

The concentrations of which two ions are highest outside the cell? Na+ and Cl− Na+ and protein anions (A−) K+ and protein anions (A−) K+ and Cl−

Na+ and Cl−

The Na+-K+ pump actively transports both sodium and potassium ions across the membrane to compensate for their constant leakage. In which direction is each ion pumped? Na+ is pumped out of the cell and K+ is pumped into the cell. K+ is pumped out of the cell and Na+ is pumped into the cell. Both Na+ and K+ are pumped into the cell. Both Na+ and K+ are pumped out of the cell.

Na+ is pumped out of the cell and K+ is pumped into the cell.

What prevents the Na+ and K+ gradients from dissipating? Na+ cotransporter Na+ and K+ leaks H+-K+ ATPase Na+-K+ ATPase

Na+-K+ ATPase

Predict what you think will happen to the ions in each compartment as soon as we allow potassium to move. No net movement of ions. Two ions move down their gradients. One ion moves down its gradients.

One ion moves down its gradients.

Which process uses clathrin in coated pits to bring substances into cells? Exocytosis Pinocytosis Receptor-mediated endocytosis Phagocytosis

Receptor-mediated endocytosis

Ions are unequally distributed across the plasma membrane of all cells. This ion distribution creates an electrical potential difference across the membrane. What is the name given to this potential difference? Action potential Threshold potential Positive membrane potential Resting membrane potential (RMP)

Resting membrane potential (RMP)

Which type of membrane transport generally requires that the transported substance dissolve in the lipid membrane? Phagocytosis Facilitated diffusion Active transport Simple diffusion

Simple diffusion

Which is NOT true about diffusion in the human body? Diffusion occurs faster at higher temperatures. Net movement of molecules occurs until the concentration is equal. Diffusion is rapid over short distances and slower over longer distances. Smaller molecules take longer to diffuse than larger ones.

Smaller molecules take longer to diffuse than larger ones.

On average, the resting membrane potential is -70 mV. What does the sign and magnitude of this value tell you? The outside surface of the plasma membrane is much more negatively charged than the inside surface. There is no electrical potential difference between the inside and the outside surfaces of the plasma membrane. The inside surface of the plasma membrane is much more negatively charged than the outside surface. The inside surface of the plasma membrane is much more positively charged than the outside surface.

The inside surface of the plasma membrane is much more negatively charged than the outside surface.

If a swimmer cuts his foot on a seashell while wading in the ocean and bleeds into the seawater, his erythrocytes will shrink. What does this tell us about the relative tonicities of the solutions? The cell membrane is not permeable to seawater. The ocean is hypertonic to the erythrocytes. The ocean is isotonic to the erythrocytes. The ocean is hypotonic to the erythrocytes.

The ocean is hypertonic to the erythrocytes.

The resting membrane potential depends on two factors that influence the magnitude and direction of Na+ and K+ diffusion across the plasma membrane. Identify these two factors. The presence of concentration gradients and leak channels The presence of concentration gradients and voltage-gated channels The presence of concentration gradients and Na+-K+ pumps The presence of a resting membrane potential and leak channels

The presence of concentration gradients and leak channels

The plasma membrane is much more permeable to K+ than to Na+. Why? Ligand-gated cation channels favor a greater influx of Na+ than K+. The Na+-K+ pumps transport more K+ into cells than Na+ out of cells. There are many more K+ leak channels than Na+ leak channels in the plasma membrane. There are many more voltage-gated K+ channels than voltage-gated Na+ channels.

There are many more K+ leak channels than Na+ leak channels in the plasma membrane.

How does the intracellular fluid compartment differ from the extracellular fluid compartment? There is a higher concentration of bicarbonate ion (HCO3-) inside cells than in either the interstitial fluid or plasma. There is a higher concentration of sodium ions inside the cell than in the extracellular space. There is a higher concentration of potassium ions inside the cell than in the extracellular space. There is a higher concentration of protein in the interstitial fluid than in cells.

There is a higher concentration of potassium ions inside the cell than in the extracellular space.

Saturation occurs when a group of carrier proteins is operating at its maximum rate. a preference of a carrier protein for a substance is demonstrated based on the differing affinities of the carrier for the substrates. the energy required to move molecules results from a high-energy bond. molecules are moved by the use of vesicles. a carrier molecule has the ability to transport only one molecule or a group of closely related molecules.

a group of carrier proteins is operating at its maximum rate.

Match the type of transport with its description. A. secretion B. paracellular transport C. transcellular transport D. absorption from an organ's lumen to the extracellular fluid

absorption

Transport of a substance from the lumen (cavity) of an organ into one side of a cell and out the other side of the cell into the ECF is called __________. absorption transcellular transport paracellular transport secretion

absorption

Match the transport process to its description. A. active transport B. passive transport the movement of molecules against the concentration gradient

active transport

Match the transport process to its description. A. active transport B. passive transport the movement of molecules via proteins embedded in the cell membrane; requires ATP

active transport

The concentration of calcium inside a cell is 0.3%. The concentration of calcium outside the cell is 0.1%. How could the cell transport even more calcium to the inside? osmosis passive transport exocytosis active transport All of the answers are correct.

active transport

Match the membrane protein with its function. A. transfer signals from the extracellular environment to the cytoplasm of the cell B. form cell-to-cell connections C. bind to molecules to facilitate entry to or exit from the cell D. ligands bind to these proteins and are changed by the protein transporters

bind to molecules to facilitate entry to or exit from the cell

Match the transport process to its description. A. simple diffusion B. facilitated diffusion C. both D. neither the movement of molecules from an area of high concentration to an area of low concentration

both

Which body fluid compartment contains higher levels of Na+, Cl-, and HCO3-? interstitial fluid plasma intracellular fluid both plasma and intracellular fluid both plasma and interstitial fluid

both plasma and interstitial fluid

During depolarization, which gradient(s) move(s) Na+ into the cell? only the chemical gradient only the electrical gradient Na+ does not move into the cell. Na+ moves out of the cell. both the electrical and chemical gradients

both the electrical and chemical gradients

A cell membrane that is selectively permeable will only allow substances in or out if their concentration in the cell is above or below a certain point. is impermeable to all substances but water. randomly chooses which substances will pass through. can change which substances pass through by changing its lipid and protein content.

can change which substances pass through by changing its lipid and protein content.

Sodium ions are more concentrated in the extracellular fluid than in the intracellular fluid. This is an example of osmotic equilibrium. electrical disequilibrium. chemical disequilibrium. failed homeostasis.

chemical disequilibrium.

Fick's law of diffusion states that the rate of diffusion across a membrane is proportional to membrane permeability, but inversely proportional to concentration gradient and surface area. surface area and membrane thickness, but inversely proportional to concentration gradient. membrane thickness and surface area. concentration gradient, surface area, and membrane permeability.

concentration gradient, surface area, and membrane permeability.

The tonicity of a solution depends only upon the __________. total concentration of solutes, taking into account that some single molecules (such as salts, e.g., NaCl) ionize into more than one solute (Na+ and Cl-) total concentration of solutes as initially added to the solvent when making the solution concentration of penetrating solutes concentration of non-penetrating solutes

concentration of non-penetrating solutes

Match the potential or potential change with the causative circumstances. Assume ion movements are net movements. A. resting membrane potential B. hyperpolarization C. depolarization D. repolarization E. more than one of the answers Na+ enters the cell

depolarization

Match the potential or potential change with the causative circumstances. Assume ion movements are net movements. A. resting membrane potential B. hyperpolarization C. depolarization D. repolarization E. more than one of the answers membrane potential is 0 mV

depolarization

Match the terms to changes presented, assuming a resting membrane potential of -70 mV. A. electrical polarization B. hyperpolarization C. depolarization D. repolarization E. more than one of the answers to +30 mV from resting potential

depolarization

Match the terms to changes presented, assuming a resting membrane potential of -70 mV. A. electrical polarization B. hyperpolarization C. depolarization D. repolarization E. more than one of the answers to -50 mV from resting potential

depolarization

As the charge on the membrane of a cell approaches 0 from -70 mV, the cell is becoming more difficult to stimulate. depolarizing. hyperpolarizing. repolarizing. hyperpolarizing and becoming more difficult to stimulate.

depolarizing.

The inside of a resting cell is slightly negative relative to the outside. This is an example of electrical disequilibrium. chemical disequilibrium. failed homeostasis. osmotic equilibrium

electrical disequilibrium.

The cell membrane acts as a good electrical conductor. source of ions. electrical insulator. electrical gradient.

electrical insulator.

Pinocytosis is a type of exocytosis. exocytosis and phagocytosis. endocytosis and exocytosis. phagocytosis. endocytosis.

endocytosis.

A cell transports large molecules out of the cell by endocytosis. diffusion. exocytosis. phagocytosis. active transport.

exocytosis.

Match the transport process to its description. A. simple diffusion B. facilitated diffusion C. both D. neither a form of mediated transport

facilitated diffusion

Which is a way for solutes to move from an area of high solute concentration to an area of low solute concentration? osmosis facilitated diffusion active transport facilitated diffusion and osmosis None of the answers are correct.

facilitated diffusion

Match the membrane protein with its function. A. transfer signals from the extracellular environment to the cytoplasm of the cell B. form cell-to-cell connections C. bind to molecules to facilitate entry to or exit from the cell D. ligands bind to these proteins and are changed by the protein structural proteins

form cell-to-cell connections

If a 10% sucrose solution is separated from a 20% sucrose solution by a membrane impermeable to sucrose, in which direction will net movement of water occur? from the 20% sucrose solution to the 10% sucrose solution from the 10% sucrose solution to the 20% sucrose solution from the 20% sucrose solution to the 10% sucrose solution and from the 10% sucrose solution to the 20% sucrose solution There will be no net movement of water in this case. None of the answers are correct.

from the 10% sucrose solution to the 20% sucrose solution

If a 10% sucrose solution is separated from a 20% sucrose solution by a membrane permeable to sucrose, in which direction will net diffusion of sucrose take place? from the 10% sucrose solution to the 20% sucrose solution from the 20% sucrose solution to the 10% sucrose solution from the 10% sucrose solution to the 20% sucrose solution and from the 20% sucrose solution to the 10% sucrose solution neither from the 10% sucrose solution to the 20% sucrose solution or from the 20% sucrose solution to the 10% sucrose solution There will be no diffusion in this case.

from the 20% sucrose solution to the 10% sucrose solution

Substances that readily dissolve in water and do not readily dissolve in lipids are hydrophilic and lipophilic. hydrophobic and lipophilic. hydrophilic and lipophobic. hydrophobic and lipophobic.

hydrophilic and lipophobic.

Match the potential or potential change with the causative circumstances. Assume ion movements are net movements. A. resting membrane potential B. hyperpolarization C. depolarization D. repolarization E. more than one of the answers Cl- enters the cell

hyperpolarization

Match the terms to changes presented, assuming a resting membrane potential of -70 mV. A. electrical polarization B. hyperpolarization C. depolarization D. repolarization E. more than one of the answers to -90 mV from resting potential

hyperpolarization

Water will always move from ________ areas to ________ areas, if the membrane is permeable to water. isotonic, hypotonic hypotonic, hypertonic hypertonic, isotonic hypertonic, hypotonic

hypotonic, hypertonic

Passive transport refers to a process that requires no energy at all. concentration gradient. input of energy. electrical gradient. pressure gradient.

input of energy.

Which body fluid compartment contains high levels of K+, large anions, and proteins? interstitial fluid intracellular fluid plasma plasma and intracellular fluid plasma and interstitial fluid

intracellular fluid

The membrane potential of most cells __________. is negative, except when there is a change in membrane permeability to ions is negative at all times is determined primarily by sodium results in a net negative electrical charge in the body

is negative, except when there is a change in membrane permeability to ions

Match the membrane protein with its function. A. transfer signals from the extracellular environment to the cytoplasm of the cell B. form cell-to-cell connections C. bind to molecules to facilitate entry to or exit from the cell D. ligands bind to these proteins and are changed by the protein enzymes

ligands bind to these proteins and are changed by the protein

Hyposmotic solutions have lower concentrations of solutes than other hyposmotic solutions. lower concentrations of solutes than hyperosmotic solutions. the same concentration of solutes as hyperosmotic solutions. higher concentrations of solutes than hyperosmotic solutions. None of the answers are correct.

lower concentrations of solutes than hyperosmotic solutions.

Permeability is a property of membranes. proteins. solvents. solutes. ions.

membranes.

Compared to the outside surface, the inside of a resting cell membrane is negatively charged. continuously reversing its electrical charge. positively charged. positively charged whenever the sodium-potassium pump is active. electrically neutral.

negatively charged.

Match the transport process to its description. A. simple diffusion B. facilitated diffusion C. both D. neither the use of ATP to move molecules

neither

Let's consider a scenario in which the resting membrane potential changes from −70 mV to +70 mV, but the concentrations of all ions in the intracellular and extracellular fluids are unchanged. Predict how this change in membrane potential affects the movement of Na+. The electrical gradient for Na+ would tend to move Na+ __________ while the chemical gradient for Na+ would tend to move Na+ __________. out; in in; in out; out in; out

out; in

Match the type of transport with its description. A. secretion B. paracellular transport C. transcellular transport D. absorption between adjacent cells

paracellular transport

Match the transport process to its description. A. active transport B. passive transport tends to create an equilibrium state

passive transport

Match the transport process to its description. A. active transport B. passive transport the movement of molecules from an area of high concentration to an area of low concentration

passive transport

What are the two extracellular fluid compartments in the body? plasma and the fluid portion of the blood intracellular fluid and plasma plasma and interstitial fluid interstitial fluid and intracellular fluid None of the answers are correct.

plasma and interstitial fluid

Bulk flow is fluid flow as a result of a(n) ________ gradient. pressure electrical concentration Two of the answers are correct. None of the answers are correct.

pressure

Match the potential or potential change with the causative circumstances. Assume ion movements are net movements. A. resting membrane potential B. hyperpolarization C. depolarization D. repolarization E. more than one of the answers K+ leaves the cell, bringing its potential back to the resting value

repolarization

Match the terms to changes presented, assuming a resting membrane potential of -70 mV. A. electrical polarization B. hyperpolarization C. depolarization D. repolarization E. more than one of the answers to -70 mV from -50 mV

repolarization

Match the terms to changes presented, assuming a resting membrane potential of -70 mV. A. electrical polarization B. hyperpolarization C. depolarization D. repolarization E. more than one of the answers to -70 mV from -90 mV

repolarization

Which is NOT involved in creating the resting potential of a cell? diffusion of potassium ions out of the cell diffusion of sodium ions into the cell resting membrane permeability for potassium ions greater than sodium ions resting membrane permeability for sodium ions greater than potassium ions

resting membrane permeability for sodium ions greater than potassium ions

Match the type of transport with its description. A. secretion B. paracellular transport C. transcellular transport D. absorption movement from the extracellular fluid into the lumen of an organ

secretion

Which is NOT a type of mediated transport? facilitated diffusion simple diffusion primary active transport secondary active transport

simple diffusion

Active transport of substances across membranes requires ATP because __________. the transport protein moves or has moving gates more than one substance is transported at a time substances are moved against the concentration gradient (uphill) the transported substances are not soluble in the lipid membrane

substances are moved against the concentration gradient (uphill)

Match the type of transport with its description. A. secretion B. paracellular transport C. transcellular transport D. absorption in one side of a cell and out the other

transcellular transport

Match the membrane protein with its function. A. transfer signals from the extracellular environment to the cytoplasm of the cell B. form cell-to-cell connections C. bind to molecules to facilitate entry to or exit from the cell D. ligands bind to these proteins and are changed by the protein receptors

transfer signals from the extracellular environment to the cytoplasm of the cell

Voltage-gated channels and antiport carriers are both types of transporters. structural proteins. enzymes. receptors.

transporters.

Which is a similarity between endocytosis and exocytosis? They both ____. are ways that LDL helps bring cholesterol into cells use membrane-bound vesicles need to be stimulated to transport substances are ways that proteins such as insulin are secreted from cells

use membrane-bound vesicles