Chapter 5 Life's Border: The Plasma Membrane
Biology: A Guide to the Natural World, 5e (Krogh)
1) The outer living limit of the cell is called the:
A) cell wall.
B) edge.
C) plastid.
D) plasma membrane.
Answer: D
Topic: Section 5.1
Skill: Knowledge/Comprehension
2) Cystic fibrosis is the result of:
A) no sodium channel protein.
B) no sodium-potassium pump.
C) an abnormal sodium channel protein.
D) an abnormal chloride channel protein.
E) cysts in the lungs.
Answer: D
Topic: Section 5.1
Skill: Knowledge/Comprehension
3) The primary component of the plasma membrane is:
A) cholesterol.
B) phospholipid.
C) protein.
D) carbohydrate.
Answer: B
Topic: Section 5.1
Skill: Knowledge/Comprehension
4) A purpose of the plasma membrane is to:
A) form the outer boundary of a cell.
B) produce proteins.
C) allow no contact with other cells.
D) keep harmful substances within the cell.
E) form ribosomes.
Answer: A
Topic: Section 5.1
Skill: Knowledge/Comprehension
5) Which of the following is an accurate description of the plasma membrane?
A) It is a phospholipid bilayer embedded with proteins.
B) It separates the nuclear contents from the environment.
C) It is permeable to all substances.
D) It is a solid material.
Answer: A
Topic: Section 5.1
Skill: Knowledge/Comprehension
6) Short chains of sugars attached to proteins or phospholipids in the cell membrane make up the:
A) phospholipid bilayer.
B) communication proteins.
C) cholesterol.
D) glycocalyx.
Answer: D
Topic: Section 5.1
Skill: Knowledge/Comprehension
7) The ________ of a phospholipid molecule will seek water, whereas the ________ of the molecules will avoid water.
A) tail; head
B) head; tail
C) hydrophobic portion; hydrophilic portion
D) fatty acid; phosphate group
Answer: B
Topic: Section 5.1
Skill: Knowledge/Comprehension
8) The huge array of capabilities of the plasma membrane are performed by its:
A) carbohydrates.
B) proteins.
C) phospholipids.
D) cholesterol.
Answer: B
Topic: Section 5.1
Skill: Knowledge/Comprehension
9) Which of the following is true of the plasma membrane?
A) It controls the passage of substances into and out of the cell.
B) It only allows hydrophilic materials to pass through.
C) It is a rigid, nonchanging structure.
D) Its capabilities are primarily determined by carbohydrates in the membrane.
Answer: A
Topic: Section 5.1
Skill: Knowledge/Comprehension
10) How does glucose enter a cell if levels of blood glucose are high?
A) An electrical signal is passed through the blood, opening glucose channels within the membranes of cells.
B) Insulin molecules bind to glucose receptors, causing cellular responses to take up glucose.
C) The glucose molecules diffuse through the membrane.
D) Glucose pokes a hole in the cell's membrane, creating a channel through which it can move.
Answer: B
Topic: Section 5.1
Skill: Knowledge/Comprehension
11) The phospholipids of membranes are:
A) hydrophilic molecules.
B) hydrophobic molecules.
C) both hydrophilic and hydrophobic molecules.
D) oils.
Answer: C
Topic: Section 5.1
Skill: Knowledge/Comprehension
12) The fatty-acid tails of a phospholipid are:
A) hydrophilic.
B) proteins.
C) polar.
D) hydrophobic.
E) carbohydrates.
Answer: D
Topic: Section 5.1
Skill: Knowledge/Comprehension
13) Small, nonpolar molecules easily pass through the phospholipid bilayer because the molecules:
A) can dissolve in the hydrophobic portion of the bilayer.
B) are brought in by attaching to structural proteins in the membrane.
C) are brought in by attaching to cholesterol in the membrane.
D) dissolve in water and follow the water as it flows into the cell.
Answer: A
Topic: Section 5.1
Skill: Knowledge/Comprehension
14) What is the role of transport proteins within the plasma membrane?
A) Transport proteins prevent the passage of amino acids through the membrane.
B) Transport proteins allow movement of ions and polar molecules through the plasma membrane.
C) Transport proteins identify the cell.
D) Transport proteins interact with the cytoskeleton to stabilize various parts of the cell.
E) Transport proteins maintain membrane fluidity.
Answer: B
Topic: Section 5.1
Skill: Knowledge/Comprehension
15) A component of the plasma membrane that helps to maintain its fluidity is:
A) protein.
B) carbohydrate.
C) nucleic acid.
D) the phospholipid bilayer.
E) cholesterol.
Answer: E
Topic: Section 5.1
Skill: Knowledge/Comprehension
16) Which statement below is true?
A) All internal cell membranes are similar in structure to the plasma membrane.
B) The only internal membrane of a cell that is similar to the plasma membrane is the nuclear membrane.
C) All internal membranes of a cell are just giant invaginations from the plasma membrane.
D) Vesicle membranes degrade as they fuse with the plasma membrane during exocytosis.
Answer: A
Topic: Section 5.1
Skill: Knowledge/Comprehension
17) The plasma membrane is composed of phospholipids, which are free to move laterally, and is peppered with both stationary and mobile proteins. This view of the plasma membrane is known as the:
A) peppered membrane model.
B) phospholipid bilayer model.
C) fluid-mosaic model.
D) semipermeable membrane model.
Answer: C
Topic: Section 5.1
Skill: Knowledge/Comprehension
18) A main function of the carbohydrates that form the glycocalyx is to:
A) move large molecules in and out of the cell.
B) regulate water movement into the cell.
C) bind cell membranes to the cytoskeleton.
D) act as binding sites for signaling molecules.
E) maintain the proper fluidity of the plasma membrane.
Answer: D
Topic: Section 5.1
Skill: Knowledge/Comprehension
19) Which type of proteins are involved in nutrient transport across the plasma membrane and why?
A) integral proteins, because they span the membrane and are able to carry nutrients across the membrane
B) peripheral proteins, because they are smaller and can travel across the membrane, thereby carrying nutrients across the membrane
C) integral proteins, because they are smaller and can travel across the membrane, thereby carrying nutrients across the membrane
D) peripheral proteins, because they span the membrane and are able to carry nutrients across the membrane
E) receptor proteins, because their carbohydrate chains bind to nutrients and carry them across the membrane
Answer: A
Topic: Section 5.1
Skill: Application/Analysis
20) Membrane proteins perform all of the following functions except:
A) structural support.
B) cell recognition.
C) communication.
D) transport.
E) maintainance of membrane fluidity.
Answer: E
Topic: Section 5.1
Skill: Knowledge/Comprehension
21) You have isolated a cell that is unable to produce cholesterol for its cell membranes. Which of the following defects is this cell most likely to have?
A) The cell membrane will not have the correct fluidity.
B) The cell will not be able to communicate with other cells.
C) The cell will be unable to transport nutrients.
D) The cell will burst as a result of osmosis.
E) The cell will not be able to regulate the transportation of substances into and out of the cell.
Answer: A
Topic: Section 5.1
Skill: Application/Analysis
22) If you transferred a phospholipid bilayer from water to oil, what effect would this have on the membrane?
A) The membrane would become very rigid.
B) The membrane would form four layers instead of its normal two.
C) The membrane would be unaffected by the oil.
D) The membrane would invert its normal structure by positioning the heads on the inside of the bilayer and the fatty-acid tails outside.
E) The phospholipid bilayer would split into two separate layers, which each would be maintained in the oil.
Answer: D
Topic: Section 5.1
Skill: Application/Analysis
23) Peripheral proteins:
A) usually span the entire membrane.
B) have no known functions in membranes.
C) act as channels through which materials can pass.
D) are defective in cystic fibrosis.
E) usually attach to integral proteins.
Answer: E
Topic: Section 5.1
Skill: Knowledge/Comprehension
24) If you could add a colored label to one phospholipid in the cell's plasma membrane to observe this molecule, what kind of movement of the molecule would you see?
A) The molecule would move rapidly back and forth across the surface of the membrane.
B) The molecule would be locked in place by its tightly packed neighbors in the plasma membrane.
C) The molecule would be converted back and forth between a receptor protein and a phospholipid.
D) The molecule would move back and forth between the membrane and the surrounding watery solution.
E) The molecule would flip back and forth from one layer of the membrane to the other.
Answer: A
Topic: Section 5.1
Skill: Application/Analysis
25) The plasma membrane is a semipermeable membrane. This means that it is:
A) permeable to small molecules except water.
B) permeable to small and uncharged molecules but not to larger or charged substances.
C) only permeable to cholesterol.
D) permeable to large charged molecules but not to small uncharged molecules.
Answer: B
Topic: Section 5.2
Skill: Knowledge/Comprehension
26) Diffusing molecules move ________ until they are ________.
A) down their concentration gradients; evenly distributed
B) up their concentration gradients; evenly distributed
C) through channels of active transport proteins; evenly distributed
D) up their concentration gradients; unevenly distributed
E) down their concentration gradients; unevenly distributed
Answer: A
Topic: Section 5.2
Skill: Knowledge/Comprehension
27) Red blood cells placed in pure water will swell and burst. What process is causing this to happen?
A) Water is diffusing across the plasma membrane from a region of high (outside the cell) to low (inside the cell) "free" water concentration.
B) Water is being pulled into the cell by the cell's solutes.
C) Water is diffusing across the plasma membrane from a region of low (outside the cell) to high (inside the cell) "free" water concentration.
D) Solutes are being drawn into the cell across the plasma membrane.
E) Ions are diffusing across the plasma membrane and destabilizing the phospholipids.
Answer: A
Topic: Section 5.2
Skill: Application/Analysis
28) The central vacuoles of some plant cells you are studying fill with water and press the cell contents against their cell walls because of osmosis. What can you predict about the concentration of solutes in the solution that bathes the turgid plant cells?
A) The concentration of solutes outside the cell must be significantly lower than the concentration within the cell.
B) The concentration of solutes outside the cell must be significantly higher than the concentration within the cell.
C) There must be no solutes either outside or inside the cell.
D) The concentration of solutes outside the cell must be about the same as that of seawater.
E) The concentration of solutes outside the cell can't be predicted, because it's the concentration inside the cell that's important.
Answer: A
Topic: Section 5.2
Skill: Application/Analysis
29) It seems that bacteria and molds should grow well in jam. It's extremely high in sugar, a substance many cells can use for energy, and contains enough other nutrients to support cell growth. Yet jam can be left unrefrigerated for a very long time without contamination by microorganisms. How can this be?
A) Bacteria and molds cannot grow on fruit products.
B) The high sugar concentration causes bacterial and mold cells to swell and rupture.
C) The high sugar concentration damages cell membranes.
D) Bacteria and molds cannot get into the jam because its high concentration of sugar makes it so sticky.
E) The high sugar concentration causes bacterial and mold cells to shrink and die.
Answer: E
Topic: Section 5.2
Skill: Application/Analysis
30) Oxygen moving through the plasma membrane down its concentration gradient is an example of:
A) simple diffusion.
B) active transport.
C) facilitated diffusion.
D) osmosis.
Answer: A
Topic: Section 5.2
Skill: Knowledge/Comprehension
31) Which statement about diffusion is correct?
A) Diffusion can occur only through a membrane.
B) Diffusion requires a protein channel.
C) Diffusion of water cannot occur.
D) Diffusion causes movement of materials toward equilibrium.
Answer: D
Topic: Section 5.2
Skill: Knowledge/Comprehension
32) Diffusion is a process by which a substance:
A) goes from lesser to greater concentration.
B) goes down its concentration gradient.
C) goes up its concentration gradient.
D) is at equilibrium.
Answer: B
Topic: Section 5.2
Skill: Knowledge/Comprehension
33) The term that describes the diffusion of water is:
A) simple diffusion.
B) equilibrium.
C) facilitated diffusion.
D) active transport.
E) osmosis.
Answer: E
Topic: Section 5.2
Skill: Knowledge/Comprehension
34) You have lost a lot of blood in an accident. In the emergency room the first thing the doctors will need to do is replace lost fluids. The fluids they give you should be:
A) isotonic to your cells.
B) hypotonic to your cells.
C) hypertonic to your cells.
D) either hypertonic or isotonic to your cells.
E) either hypertonic or hypotonic to your cells.
Answer: A
Topic: Section 5.2
Skill: Application/Analysis
35) Plants stay standing upright because of turgor pressure caused by:
A) water rushing into the cells, keeping the cells tight.
B) solutes rushing into the cells, keeping the cells tight.
C) bones that run through the plant, holding it upright.
D) cell walls of the plants supporting and keeping the plants standing upright.
Answer: A
Topic: Section 5.2
Skill: Knowledge/Comprehension
36) Water moves from a:
A) hypotonic environment to a hypertonic environment.
B) hypertonic environment to a hypotonic environment.
C) low free-water solution toward a high free-water solution.
D) solution with more salt to a solution with less salt.
Answer: A
Topic: Section 5.2
Skill: Knowledge/Comprehension
37) Which of the following would be least likely to diffuse through a phospholipid bilayer?
A) carbon dioxide
B) water
C) the small, nonpolar molecule of butane
D) oxygen
E) sodium ions
Answer: E
Topic: Section 5.3
Skill: Application/Analysis
38) One difference between passive and active transport through a cell membrane is that:
A) active transport makes ATP.
B) active transport requires ATP.
C) passive transport requires ATP.
D) passive transport makes ATP.
Answer: B
Topic: Section 5.3
Skill: Knowledge/Comprehension
39) Facilitated diffusion occurs with the help of:
A) recognition proteins.
B) peripheral proteins.
C) transport proteins.
D) communication proteins.
E) ribosomes.
Answer: C
Topic: Section 5.3
Skill: Knowledge/Comprehension
40) Active transport:
A) moves only large molecules into the cell.
B) causes the production of ATP within the cell.
C) increases the concentration of solute inside the cell.
D) moves substances against their concentration gradient.
Answer: D
Topic: Section 5.3
Skill: Knowledge/Comprehension
41) Facilitated diffusion is similar to simple diffusion because:
A) each requires the use of energy.
B) each requires a protein channel for movement to occur.
C) in both, materials move down their concentration gradient.
D) each utilizes vesicles to move material around the cell.
Answer: C
Topic: Section 5.3
Skill: Application/Analysis
42) The sodium-potassium pump is an example of:
A) passive transport.
B) receptor-mediated endocytosis.
C) facilitated diffusion.
D) active transport.
Answer: D
Topic: Section 5.3
Skill: Applied
43) Calcium ions (Ca2+) are present in the endoplasmic reticulum at concentrations 1,000 times higher than in the cytosol (the gel-like part of the cell outside organelles). One protein on the endoplasmic reticulum membrane is devoted to allowing Ca2+ to move from the endoplasmic reticulum to the cytosol, and another protein moves Ca2+ from the cytosol to the endoplasmic reticulum. These processes are not trivial–Ca2+ released into the cytosol allows, for example, for muscle contraction and communication between nerve cells. In this pair of Ca2+ transport proteins, you would predict that the protein moving Ca2+ from the endoplasmic reticulum to the cytosol ________, and the protein that moves Ca2+ from cytosol to the endoplasmic reticulum ________.
A) transports calcium slowly; transports calcium rapidly
B) works without ATP; requires ATP
C) requires ATP; works without ATP
D) is large; is small
E) is small; is large
Answer: B
Topic: Section 5.3
Skill: Application/Analysis
44) Yeast cells take up glucose (a sugar) to use as their primary source of energy. Typically, glucose concentrations outside yeast cells are far lower than glucose concentrations inside the cells. Therefore, for yeast to take up glucose, the cells must use:
A) facilitated diffusion to move glucose down its concentration gradient.
B) active transport to move glucose up its concentration gradient.
C) facilitated diffusion to move glucose up its concentration gradient.
D) active transport to move glucose down its concentration gradient.
E) osmosis to directly absorb glucose.
Answer: B
Topic: Section 5.3
Skill: Application/Analysis
45) All of the following processes bring materials into a cell except:
A) endocytosis.
B) receptor-mediated endocytosis.
C) exocytosis.
D) phagocytosis.
Answer: C
Topic: Section 5.4
Skill: Knowledge/Comprehension
46) Phagocytosis is a type of ________ in which a cell engulfs another cell.
A) passive transport
B) active transport
C) facilitated diffusion
D) endocytosis
E) exocytosis
Answer: D
Topic: Section 5.4
Skill: Knowledge/Comprehension
47) Insulin and many other hormones are protein molecules. Based on your knowledge of transport processes, you can say that cells that secrete these types of hormones do so through:
A) facilitated diffusion.
B) pinocytosis.
C) passive diffusion.
D) receptor-mediated endocytosis.
E) exocytosis.
Answer: E
Topic: Section 5.4
Skill: Application/Analysis
48) The 1985 Nobel Prize in Physiology or Medicine was awarded to Michael Brown and Joseph Goldstein for their work on cholesterol metabolism. Brown and Goldstein investigated the cause of remarkably high levels of circulating cholesterol found in certain families. Just as remarkable was the high incidence of heart disease in these families. What Brown and Goldstein found was not what might be expected–these individuals did not make too much cholesterol. Instead, most of these people had defects in receptor-mediated endocytosis (RME). What could possibly link high cholesterol levels in the blood and defective RME in these patients?
A) Cholesterol was being secreted from cells by RME at too high a rate and therefore accumulated in the blood.
B) Cholesterol was not transported into cells by RME and therefore accumulated in the blood.
C) Cholesterol was being secreted by facilitated diffusion at too high a rate and therefore accumulated in the blood.
D) Cholesterol was not transported into cells by active transport proteins and therefore accumulated in the blood.
E) Cholesterol was not transported into cells by facilitated diffusion and therefore accumulated in the blood.
Answer: B
Topic: Section 5.4
Skill: Application/Analysis
49) The hydrophilic region of the phospholipid bilayer faces to the interior of the plasma membrane.
Answer: FALSE
Topic: Section 5.1
Skill: Knowledge/Comprehension
50) In cystic fibrosis, cells cannot pump out enough chloride ions.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
51) Having defective proteins in the cell membrane can cause disease.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
52) The hydrophilic heads of phospholipids in the plasma membrane face a water-based environment.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
53) Cholesterol is a hormone receptor in the plasma membrane.
Answer: FALSE
Topic: Section 5.1
Skill: Knowledge/Comprehension
54) Integral proteins always extend completely through the plasma membrane.
Answer: FALSE
Topic: Section 5.1
Skill: Knowledge/Comprehension
55) The chief component of the plasma membrane is the phospholipid bilayer.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
56) The glycocalyx is found just inside the plasma membrane of the cell.
Answer: FALSE
Topic: Section 5.1
Skill: Knowledge/Comprehension
57) Carbohydrate chains serve as the binding sites for many signaling molecules.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
58) Hydrophobic molecules easily pass through the fatty-acid region of the plasma membrane.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
59) Signals sent between cells reach a cell at receptor proteins.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
60) Cholesterol helps to maintain the correct fluidity of the plasma membrane.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
61) The phospholipid bilayer forms spontaneously in water.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
62) The phospholipid bilayer forms because fatty-acid tails do not dissolve in water.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
63) Transport proteins are integral plasma membrane proteins.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
64) Some integral proteins can span the entire phospholipid bilayer.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
65) The functioning of the immune system depends on recognition proteins.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
66) The most up-to-date explanation of the structure of the plasma membrane is called the fluid-mosaic model.
Answer: TRUE
Topic: Section 5.1
Skill: Knowledge/Comprehension
67) Water moves freely through a semipermeable membrane.
Answer: TRUE
Topic: Section 5.2
Skill: Knowledge/Comprehension
68) Osmosis is an example of passive transport.
Answer: TRUE
Topic: Section 5.2
Skill: Knowledge/Comprehension
69) Diffusion occurs because of random molecular movement.
Answer: TRUE
Topic: Section 5.2
Skill: Knowledge/Comprehension
70) A cell wall stops a plant cell from taking in so much water that it will burst.
Answer: TRUE
Topic: Section 5.2
Skill: Knowledge/Comprehension
71) A substance moving down the concentration gradient is an example of active transport.
Answer: FALSE
Topic: Section 5.3
Skill: Knowledge/Comprehension
72) Facilitated diffusion occurs through membrane-bound transport proteins.
Answer: TRUE
Topic: Section 5.3
Skill: Knowledge/Comprehension
73) Facilitated diffusion occurs down a concentration gradient.
Answer: TRUE
Topic: Section 5.3
Skill: Knowledge/Comprehension
74) Active transport moves a substance against the concentration gradient.
Answer: TRUE
Topic: Section 5.3
Skill: Knowledge/Comprehension
75) To move a molecule into a cell against the concentration gradient requires energy.
Answer: TRUE
Topic: Section 5.3
Skill: Knowledge/Comprehension
76) Exocytosis is an example of active transport of a substance into the cell.
Answer: FALSE
Topic: Section 5.4
Skill: Knowledge/Comprehension
77) Phagocytosis is an example of passive transport.
Answer: FALSE
Topic: Section 5.4
Skill: Knowledge/Comprehension
Match the following.
A) passive transport
B) facilitated diffusion
C) simple diffusion
D) exocytosis
E) active transport
F) endocytosis
78) The movement of molecules down their concentration gradient without the use of a transport protein
Topic: Section 5.3
Skill: Knowledge/Comprehension
79) Uses transport proteins to assist the movement of materials down a concentration gradient
Topic: Section 5.3
Skill: Knowledge/Comprehension
80) Movement of materials across a cell membrane that does not require energy
Topic: Section 5.3
Skill: Knowledge/Comprehension
81) Requires the expenditure of energy to move molecules or ions across a cell membrane
Topic: Section 5.3
Skill: Knowledge/Comprehension
82) Uses a transport vesicle to bring large materials into the cell
Topic: Section 5.4
Skill: Knowledge/Comprehension
83) Uses a transport vesicle to release materials to the exterior of a cell
Topic: Section 5.4
Skill: Knowledge/Comprehension