AP Biology Chapter 7- Membrane

The voltage across a membrane is called the _____. a) electrochemical gradient B) membrane potential c) osmotic potential d) chemical gradient

B) membrane potential

Familial hypercholesterolemia is characterized by which of the following? A) inhibition of the cholesterol active transport system in red blood cells B) poor attachment of the cholesterol to the extracellular matrix of cells C) defective LDL receptors on the cell membranes D) a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes

C) defective LDL receptors on the cell membranes

The solutions in the arms of a U - tube are separated at the bottom of the tube by selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side a is filled with a solution of .4 M glucose and .5 M sodium chloride, and side B is filled with a solution containing .8 M glucose and .4 M sodium chloride. Initially the volume in both arms is the same. In the U-tube experiment illustrated above, which of the following statements correctly describes side b at equilibrium? A) the concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will decrease B) the concentration of NaCl and glucose will increase, and the water level will decrease C) the concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will increase D) the concentration of NaCl and glucose will decrease, and the water level will increase

C) the concentration of NaCl will increase, the concentration of glucose will decrease, and the water level will increase

which component of the accompanying figure is hydrophilic? A B C D

D

In what way do the membranes of a eukaryotic cell vary? A) Only certain membranes of the cell are selectively permeable. B) Some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm. C) Phospholipids are found only in certain membranes. D) Certain proteins are unique to each membrane.

D) Certain proteins are unique to each membrane.

a patient was involved a serious accident and lost a large quantity of blood. In an Attempt to replenish body fluids, distilled water equal to the volume of blood loss is added to the blood directly via one of his veins. What will be the most probable result of this transfusion? A) The patients red blood cells will burst because the blood has become hypertonic compared to the cells B) The patient's red blood cells will shrivel up because the blood has become hypotonic compared to the cells C) The patient red blood cells will shrivel up because the blood has become hypertonic compared to the cells D) The patient's red blood cells will swell and possibly burst because the blood has become hypotonic compared to the cells

D) The patient's red blood cells will swell and possibly burst because the blood has become hypotonic compared to the cells

The solutions in the two arms of this U-tube or separated by a membrane that is permeable to water and glucose but not to sucrose. Side A is half filled with a solution of 2 M sucrose and 1M glucose. Side B is half filled with 1 M sucrose and 2 M glucose. Initially, the liquid levels on both sides are equal. Which of the following will be true when the system illustrated above reaches equilibrium? A)The water level will be higher in side B than in side A. B) The concentration of sucrose on side A will be greater than the concentration of sucrose on side B. C) The water levels will be unchanged. D) The water levels will be higher in side A than in side B

D) The water levels will be higher in side A than in side B

Three lab groups carried out an experiment to identify the concentration of sucrose and six solutions. Each unknown contains one of the following sucrose concentrations: 0 M, .2 M, .4 M .6 M .8 M & negative 1 M. Cubes of sweet potato were soaked for 24 hours in each solution and wade to determine the change in mass. Each data entry represents the average of three sample replicates expressed as a percent change in mass following a 24 hour soak in the unknown solutions from the data given which statement most accurately describes what is occurring in response to a particular unknown solution? A) unknown solution E contains the highest concentration of sucrose and the change in mass is due to the active transport of sucrose out of the cell B) Passive transport of sucrose out of the potato cells explains the change in mass observed for unknown solution F C) osmosis of water molecules from unknown solution be likely caused the increase in mass observed D) unknown solution see represents a sucrose concentration slightly higher than the molarity of sweet potato cells that water is transported out of the cells

D) unknown solution see represents a sucrose concentration slightly higher than the molarity of sweet potato cells that water is transported out of the cells

In what ways do the membranes of a eukaryotic cell vary? a) only certain membranes are constructed from amphipathic molecules. b) phospholipids are found only in certain membranes c) certain proteins are unique to each membrane d) only certain membranes of the cell are selectively permeable

In what ways do the membranes of a eukaryotic cell vary? a) only certain membranes are constructed from amphipathic molecules. b) phospholipids are found only in certain membranes c) certain proteins are unique to each membrane d) only certain membranes of the cell are selectively permeable

Which component in the accompanying figure is a protein fiber of the extracellular matrix? a) A b) B c) C d) E

a) A

which of the following factors would tend to increase membrane fluidity? a) a greater proportion of unsaturated phospholipids b) randomly oriented I the membrane, with no fixed inside-outside polarity c) a relatively high protein content in the membrane d) a lower temperature

a) a great proportion of unsaturated phospholipids

The solutions in the arms of a U-tube are separated at the bottom of the tube by selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side a is filled with a solution of .4 M glucose and .5 M Sodium chloride, inside B is filled with a solution containing .8 M glucose and .4 M sodium chloride. Initially, the volume in both arms is the same. -At the beginning of the U-tube experiment illustrated above, which of the following statements is true? a) Side A is hypotonic to side B. b) Side A is hypertonic to side B. c) Side A is hypertonic to side B with respect to glucose. d) Side A is hypotonic to side B with respect to NaCl

a) Side A is hypotonic to side B.

in which of the following environments would there. be the greatest need for osmoregulation? a) a salmon moving from a river to an ocean b) a plant being grown hydroponically in a watery mixture of designated nutrients c) a red blood cell surrounded by plasma d) an animal connective tissue cell bathed in isotonic body fluid

a) a salmon moving from a river to an ocean

Which of the following statements is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal? a) a substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose b) sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell c)sodium and glucose compete for the same binding site in the cotransporter D) glucose entering the cell down its concentration gradient provides energy for uptake of sodium ions against the electrochemical gradient

a) a substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose

based on figure 7.18, which of these experimental treatments would increase the rate of sucrose transport into a plant cell a) decreasing extracellular pH b) Decreasing extracellular sucrose concentration c) adding a substance that makes the membrane more permeable to the hydrogen ions d) decreasing cytoplasmic pH

a) decreasing extracellular pH

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly.... a) embedded in a lipid bilayer b) randomly oriented in the membrane, with no fixed inside-outside polarity c) confined to the hydrophobic interior of the membrane d) spread in a continuous layer over the inner and outer surfaces of the membraneterm-0

a) embedded in a lipid bilayer

Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a 1.5 M salt solution become limp and soft. From this we can deduce that the fresh water... a) is hypotonic and the salt solution is hypertonic to the cells of the celery stalks b) is hypertonic and the salt solution is hypotonic to the cells of the celery stalks c) is isotonic and the salt solution is hypertonic to the cells of the celery stalks d) and the salt solution are both hypertonic to the cells of the celery stalks

a) is hypotonic and the salt solution is hypertonic to the cells of the celery stalks

which of the following statements describes a characteristic feature of a carrier protein in a plasma membrane? a) it exhibits specificity for a particular type of molecule b) it works against diffusion c) it has no hydrophobic regions d) it requires the expenditure of cellular energy to function

a) it exhibits specificity for a particular type of molecule

In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they end up after endocytosis? a) on the inside surface of the vesicle b) on the outside of he vesicles c) on the inside surface of the cell membrane d) on the outer surface of the nucleus

a) on the inside surface of the vesicle

When a plant cell, such as one from a tulip leaf, is submerged in a very hypertonic solution, what is likely to occur? a) plasmolysis will shrink the interior of the cell b) the cell will become turgid c) the cell will burst d) the cell will become flaccid

a) plasmolysis will shrink the interior of the cell

What will happen to a red blood cell (RBC), which has an internal ion content of about .9% if it is placed into a beaker of pure water? a) the cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC b) the cell would shrink because the water in the beaker is hypotonic relative to the cytoplasm of the RBC c) the cell will remain the same size because the solution outside the cell is isotonic d) the cell would shrink because the water in the beaker is hypertonic relative to the cytoplasm of the RBC

a) the cell would swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC

A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in..... a)lysosomes b) Golgi vesicles c) secretory vesicles d) vacuoles

a)lysosomes

The solutions in the two arms of this u-tube are separated by a membrane that is permeable to water and glucose but not by sucrose. Side A is half filled with a solution 2 M Sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M Sucrose. initially, the liquid levels on both sides are equal. -When the system illustrated above reaches equilibrium, the sugar concentrations on both sides of the u-tube will be ..... a) 2 M sucrose, 1 M glucose b) 1.5 M sucrose, 1.5 M glucose c) 1 M sucrose, 2 M glucose d) 1 M sucrose, 1 M glucose

b) 1.5 M sucrose, 1.5 M glucose

Which component in the accompanying figure plays a critical role in cell-cell recognition? a) A b) B c) C d) E

b) B

which of the following types of molecules lack hydrophilic domains? a) peripheral membrane proteins b) cholesterol c)integral membrane proteins d) transmembrane proteins

b) cholesterol

The membranes of winter wheat are able to remain fluid when it is extremely cold by _____. a) decreasing the percentage of cholesterol molecules in the membrane b) increasing the proportion of unsaturated phospholipids in the membrane c) decreasing the number of hydrophobic proteins in the membrane d) increasing the proportion of the glycolipids in the membrane

b) increasing the proportion of the unsaturated phospholipids in the membrane

Which of the following membrane activities requires energy from ATP hydrolysis? a)movement of carbon dioxide b) movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid c) facilitated diffusion of chloride ions across the membrane through a chloride channel d) movement of glucose molecules into a bacterial cell from a medium containing a higher concentration of glucose than inside the cell

b) movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid

which of the following types of molecules are hydrophilic and therefore excluded from the hydrophobic portion of the phospholipid bilayer? a) integral membrane proteins b) peripheral membrane proteins c) transmembrane proteins d) cholesterol

b) peripheral membrane proteins

White blood cells engulf bacteria using.. a) osmosis b) phagocytosis c) receptor -mediated exocytosis d) pinocytsis

b) phagocytosis

Which of the following statements correctly describes osmosis? a) in osmosis, solutes move across a membrane from areas of lower water concentration to areas of higher water concentration b)In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration c) osmosis is an energy-demanding or "active" process d) osmosis only take place in red blood cells

b)In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration

Cell membranes have distinct inside and outside faces. Which of the following statements is the most likely explanation for the membranes asymmetrical nature? a) Since cell membranes communicate signals from one organism to another, the cell membranes must asymmetrical b)the two sides of a cell membrane face different environments and carry out different functions c) since the cell membrane forms a border between one cell and another in tightly packed tissues such as epithelium, the membrane must be asymmetrical d) proteins only function on the cytoplasmic side of the cell membrane, which results in the membranes asymmetrical nature

b)the two sides of a cell membrane face different environments and carry out different functions

Five dialysis bags, constructed of a type of membrane that is permeable to water and impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of .6 M sucrose solution. At 10 minute intervals, The bags were massed, and the percent change in the mass of each bag was graphed. Which line in the graph represents the bag that contained a solution isotonic to the .6 M solution at the beginning of the experiment? A B C D

c

According to the fluid mosaic model of cell membranes, phospholipids _____. a) frequently flip flop from one side of the membrane to the other b) have hydrophilic tails in the interior of the membrane c) can move laterally along the plane of the membrane d) occur in an uninterrupted bilayer, with the membrane proteins restricted to the surface of the membrane

c) can move laterally along the plane of the membrane

an animal lacking carbohydrates on the external surface of its plasma membrane would likely be impaired in which function? a) transporting ions against an electrochemical gradient b) attaching the plasma membrane to the cytoskeleton c) cell-cell recognition d) establishing a diffusion barrier to charged molecules

c) cell-cell recognition

Several epidemic microbial diseases of earlier centuries incurred high death rates because they resulted in severe dehydration due to vomiting and diarrhea. Today they are usually not fatal because we have developed which of the following? a) antiviral medications that are efficient and work well with most viruses b) medications to slow blood loss c) hydrating drinks with high concentrations of salt and glucose d) intravenous feeding techniques

c) hydrating drinks with high concentrations of salt and glucose

According to the fluid mosaic model of membrane structure, a membrane...... a) is composed of a single layer of the fluid phospholipids between two layers of hydrophilic proteins b) is composed of the mosaic of fluid polysaccharides and amphipathic proteins c) is composed of a fluid bilayer of phoholipids with embedded amphipathic proteins d)is composed of a fluid bilayer of phospholipids between two layers of hydrophilic proteins

c) is composed of a fluid bilayer of phoholipids with embedded amphipathic proteins

The difference between Pinocytosis and receptor-mediated endocytosis is that.... a) pinocytosis increases the surface are of plasma membrane, whereas receptor-mediated endocytosis decreases the plasma membrane surface area b) pinocytosis can concentrate substances from the extracellular fluid, but receptor-mediated endocytosis cannot c) pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectively d) pinocytosis brings only water molecules into the cell, but receptor-mediated endocytosis brings in other molecules as well

c) pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectively

A research team is working on the design of a new drug for the treatment of lung cancer, To be most effective, the drug must specifically enter the cytoplasm of lung cells while not entering the cell of other tissues. Which of the following characteristics would likely enhance the specificity of the drug? a) specificity of the drug molecules for binding to the extracellular metric of lung cells b) the relative hydrophobicity of the drug molecule c) similarity of the drug molecule to other molecules normally transported lung cells d) phospholipid composition of lung cell plasma membranes

c) similarity of the drug molecule to other molecules normally transported lung cells

What kinds of molecules pass through a cell membrane most easily? a) small and ionic b) large and hydrophobic c) small and hydrophobic d) large polar

c) small and hydrophobic

Which of the following are least likely to diffuse through the phospholipid bilayer of a cell membrane? a) carbon dioxide b) small hydrophobic molecules c) small ions d) large hydrophobic molecules

c) small ions

When a cell is in equilibrium with its environment, which of the following occurs for substances that can diffuse through the plasma membrane? a) there is directed movement of substance into and out of the cell b) there is no movement of substances into or out of the cell c) there is random movement of substances into and out of the cell d)all movement of molecules of across the plasma membrane occurs by active transport

c) there is random movement of substances into and out of the cell

which of the following molecules dramatically increases the rate of diffusion of water coarse cell membranes? a) gated ion channels b) the sodium-potassium pump c) ATP d) Aquaporins

d) Aquaporins

which of the following would likely diffuse through the lipid bilayer of a plasma membrane most rapidly? a) amino acid b) Na+ c) sucrose d) O2

d) O2

The diffusion of ions across membranes through specific ion channels is driven by.... A) electrical gradients only b) ACTIVE TRANSPORT PUMPS c) Ions concentration gradients only d) ion electrochemical gradients

d) ion electrochemical gradients

which of the following processes includes all the others? a) diffusion of a solute across a membrane b) transport of an ion down its electrochemical gradient c) osmosis d) passive transport

d) passive transport

The solutions in the two arms of this U-tube are separated by a membrane that is permeable to water and glucose but not to sucrose. Side a is half filled with a solution of 2M sucrose and 1M glucose. Side B is half filled with 1M sucrose and 2M glucose. Initially the liquid levels on both sides are equal. in the u- tube illustrated above,...... A) side A is hypotonic to sideB b) side a is hypertonic to side b c) side a is more turgid than side b d) side a is isotonic to side b

d) side a is isotonic to side b

Which of the following statements is a reasonable explanation for why unsaturated fatty acids help keep a membrane more fluid at lower temperature? a) unsaturated fatty acids have a higher cholesterol content, which prevents adjacent lipids from packing tightly. b)the double bonds block interaction among the hydrophilic head groups of the lipids c) unsaturated fatty acids are more non polar than saturated fatty acids d) the double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly

d) the double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly

The force driving simple diffusion is _____, while the energy source for active transport is _____. a) a concentration gradient; ADP b) transmembrane pumps; an electrochemical gradient c) phosphorylated carrier proteins; ATP d)a concentration gradient; ATP hydrolysis

d)a concentration gradient; ATP hydrolysis

Which of the following statements about diffusion is true? a) it requires an expenditure of energy by the cell b) it is very rapid over long distances c) it is inactive process in which molecules move from a region of lower concentration to a region of higher concentration d)it is a passive process in which molecules moves from a region of higher concentration to a region of lower concentration

d)it is a passive process in which molecules moves from a region of higher concentration to a region of lower concentration