Bio Chapter 7

Which of the following statements best describes a characteristic feature of a carrier protein in a plasma membrane? It requires the expenditure of cellular energy to function. It has no hydrophobic regions. It works against a concentration gradient. It exhibits specificity for a particular type of molecule.

It exhibits specificity for a particular type of molecule.

Which of the following statements about diffusion is true? It always requires integral proteins of the cell membrane. It is a passive process. It requires expenditure of energy by the cell. It occurs when molecules move from a region of lower concentration to a region of higher concentration. It is very rapid over long distances.

It is a passive process.

Which of the following statements concerning carbohydrates associated with the plasma membrane is correct? Carbohydrates on the plasma membrane are typically short chains of between two and five monosaccharides. Carbohydrates are only found associated with the membranes of prokaryotic cells. The carbohydrate composition of most eukaryotic plasma membranes is quite similar. Carbohydrates associated with the plasma membrane are located on both surfaces of the membrane. Membrane carbohydrates function primarily in cell-cell recognition.

Membrane carbohydrates function primarily in cell-cell recognition.

Which of these fatty acids is saturated and which is unsaturated?

Saturated: Palmitic Acid Unsaturated: Palmitoleic Acid and Oleic Acid

Which of the following statements about a typical plasma membrane is correct? Phospholipids are the primary component that determines which solutes can cross the plasma membrane. Carbohydrates on the membrane surface are important in determining the overall bilayer structure. The hydrophilic interior of the membrane is composed primarily of the fatty acid tails of the phospholipids. The two sides of the plasma membrane have different lipid and protein composition. The plasma membrane is a covalently linked network of phospholipids and proteins that controls the movement of solutes into and out of a cell.

The two sides of the plasma membrane have different lipid and protein composition.

A only

Which of these can RAPIDLY pass directly through the phospholipids of the plasma membrane, without the help of a transport protein?

Hypertonic Solution...lost water

You know that this cell is in a(n) _____ solution because it _____.

Hypotonic....swelled

You know that this cell is in a(n) _____ solution because the cell _____.

A red blood cell placed in a hypertonic solution will shrink in a process called ______.

crenation

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

embedded in a lipid bilayer.

A phospholipid also has two "tails" made up of two _______ molecules, which consist of a carboxyl group with a long hydrocarbon chain attached.

fatty acid

A red blood cell placed in a hypotonic solution will swell and potentially burst in a process call _______.

hemolysis

Because the phosphate group and its attachments are either charged or polar, the phospholipid head is __________, which means it has an affinity for water.

hydrophilic

A phospholipid has a "head" made up of glycerol molecule attached to a single _________________, which is attached to another small molecule.

phosphate group

Which of the following types of molecules are the major structural components of the cell membrane? phospholipids and cellulose nucleic acids and proteins phospholipids and proteins proteins and cellulose glycoproteins and cholesterol

phospholipids and proteins

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

small ions

turgid

swollen and distended or congested.

You can recognize the process of pinocytosis when _____. a receptor protein is involved the cell is engulfing a large particle the cell is engulfing extracellular fluid

the cell is engulfing extracellular fluid

The internal solute concentration of a plant cell is about 0.8M. To demonstrate plasmolysis, it would be necessary to suspend the cell in what solution? distilled water 150m 0.8M 0.4M 1.0M

1.0M

Which of the following plant cells would exhibit the most turgor pressure? A cell placed in an isotonic solution None of the listed responses is correct. A cell placed in a hypertonic solution All of the listed responses are correct. A cell placed in a hypotonic solution

A cell placed in a hypotonic solution

Which of the following would be least likely to diffuse through a plasma membrane without the help of a transport protein? Dissolved gases such as oxygen or carbon dioxide Any of the above would easily diffuse through the membrane. A small nonpolar molecule A large nonpolar molecule A large polar molecule

A large polar molecule

Which of the following substances would be most likely to pass through the plasma membrane without the help of a transport protein? Glucose A nonpolar molecule, such as a hydrocarbon A large polar molecule Water A negatively charged ion

A nonpolar molecule, such as a hydrocarbon

Which of the following is a correct difference between active transport and facilitated diffusion? Active transport involves transport proteins, and facilitated diffusion does not. Active transport can move solutes in either direction across a membrane, but facilitated diffusion can only move in one direction. Facilitated diffusion involves transport proteins, and active transport does not. Facilitated diffusion can move solutes against a concentration gradient, and active transport cannot. Active transport requires energy from ATP, and facilitated diffusion does not.

Active transport requires energy from ATP, and facilitated diffusion does not.

How does cholesterol affect membrane fluidity? At body temperature, it makes the membrane less fluid. At body temperature, it makes the membrane more fluid. At lower temperatures, it makes the membrane more fluid. It allows phospholipids to pack tightly together. It has no effect on membrane fluidity.

At body temperature, it makes the membrane less fluid.

Cells A and B are the same size, shape, and temperature, but cell A is metabolically less active than cell B; cell B is actively converting oxygen to water in cellular respiration. Oxygen will diffuse more rapidly into cell __________ because __________. B; the oxygen molecules inside cell B have a higher kinetic energy B; the diffusion gradient in cell B is steeper A; the diffusion gradient there is shallower B; the gradient of oxygen is oriented in the opposite direction compared to cell A A; its membrane transport proteins will not be saturated

B; the diffusion gradient in cell B is steeper

Why is energy required for active transport? To allow the movement of water from a hypotonic solution to a hypertonic solution To allow the movement of solutes down their concentration gradient To allow the movement of water from a hypotonic solution to a hypertonic solution Because it helps maintain water balance in cells without walls Because it moves solutes against their concentration gradient

Because it moves solutes against their concentration gradient

If a red blood cell and a plant cell were placed in seawater, what would happen to the two types of cells? The red blood cell would burst, and the plant cell would shrink. Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall. Seawater is isotonic to both cells, therefore, neither cell will change as there will be no movement of water into or out of the cells. The red blood cell would shrink, and the plant cell would gain water. Both cells would gain water by osmosis; the red blood cell would burst, and the plant cell would increase in turgor pressure.

Both cells would lose water; the red blood cell would shrivel, and the plant plasma membrane would pull away from the cell wall.

Which of the following molecules is most likely to passively diffuse across the plasma membrane? Hemoglobin Glucose Sodium ion Carbon dioxide DNA

Carbon dioxide

What function do carbohydrates fulfill in the plasma membrane? They facilitate enzymatic processes. They contribute to its "fluid" characteristic. Cell-to-cell recognition Transport of molecules across the membrane They contribute to its selective permeability.

Cell-to-cell recognition

A red blood cell is placed into each of the following solutions. Indicate whether crenation, hemolysis, or neither will occur. Solution A: 3.21% (m/v) NaCl Solution B: 1.65% (m/v) glucose Solution C: distilled H2O Solution D: 6.97% (m/v) glucose Solution E: 5.0% (m/v) glucose and 0.9% (m/v) NaCl

Crenation: Solution A, Solution D, Solution E Hemolysis: Solution B, Solution C

A nursing infant is able to obtain disease-fighting antibodies, which are large protein molecules, from its mother's milk. These molecules probably enter the cells lining the baby's digestive tract via which process? Endocytosis Active transport Osmosis Passive transport Exocytosis

Endocytosis

Which of the following processes and organelle(s) accounts for the replacement of lipids and proteins lost from the plasma membrane? Exocytosis and smooth and rough ER Flip-flop of phospholipids from one side of the plasma membrane to the other and the Golgi Receptor-mediated endocytosis and smooth ER and Golgi Endocytosis and Golgi Active transport and the rough endoplasmic reticulum

Exocytosis and smooth and rough ER

Which of these statements describes some aspect of facilitated diffusion? Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane. There is only one kind of protein pore for facilitated diffusion. Facilitated diffusion of solutes occurs through phospholipid pores in the membrane. Facilitated diffusion is another name for osmosis. Facilitated diffusion requires energy to drive a concentration gradient.

Facilitated diffusion of solutes may occur through channel or transport proteins in the membrane.

Because the C-H bonds in the fatty acid tails are relatively nonpolar, the phospholipid tails are _________, which means they are excluded from water.

Hydrophobic

Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are Hypotonic to both fresh water and the salt solution Hypertonic to both fresh water and the salt solution Hypertonic to fresh water but hypotonic to the salt solution Hypotonic to fresh water but hypertonic to the salt solution Isotonic with fresh water but hypotonic to the salt solution

Hypertonic to fresh water but hypotonic to the salt solution

Which of the following statements about passive transport is correct? Passive transport operates independently of the concentrations of the moving solute. In passive transport, solute movement stops when the solute concentration is the same on both sides of the membrane. Passive transport does not occur in the human body. Passive transport permits the solute to move in either direction, but the net movement of the population of solute molecules occurs down the concentration gradient of the molecule. Passive transport operates independently of diffusion.

Passive transport permits the solute to move in either direction, but the net movement of the population of solute molecules occurs down the concentration gradient of the molecule.

Which of the following molecules are most abundant in the plasma membrane? Cholesterol Carbohydrates Phospholipids Proteins Water

Phospholipids

Which of the following statements about the role of phospholipids in the structure and function of biological membranes is correct? Phospholipids form a structure in which the hydrophobic portion faces outward. Phospholipids form a single sheet in water. Phospholipids are completely insoluble in water. Phospholipids form a selectively permeable structure. They are triacylglycerols, which are commonly available in foods.

Phospholipids form a selectively permeable structure.

Which of the following cell structures exhibits selective permeability between a cell and its external environment? Endoplasmic Lysosomes Chloroplasts Mitochondria Plasma membrane

Plasma membrane

Which of the following structural arrangements of the components in biological membranes facilitates the cell membrane's property of selective permeability? Phospholipids sandwiched between two layers of protein A layer of protein coating a layer of phospholipid Proteins sandwiched between two layers of phospholipids A phospholipid bilayer with proteins scattered on the surfaces of the membranes Proteins embedded in two layers of phospholipids

Proteins embedded in two layers of phospholipids

How does the "fluid mosaic model" describe the structure of the plasma membrane? None of the listed responses is correct. The fluid characteristic is due to the presence of carbohydrates, and the mosaic characteristic is due to the presence of phospholipids. Proteins in the membrane contribute to the mosaic quality of the membrane while the lateral and rotational movements of phospholipids contribute to its fluidity. Only the proteins in the membrane contribute to its fluidity. The plasma membrane is a rigid structure that exhibits little flexibility.

Proteins in the membrane contribute to the mosaic quality of the membrane while the lateral and rotational movements of phospholipids contribute to its fluidity.

Determining water movement in osmosis. A semipermeable membrane is placed between the following solutions. Which solution will decrease in volume? Solution A: 1.4% (m/v) starch Solution B: 7.62% (m/v) starch

Solution A: 1.4% (m/v) starch

Further exploration of the movement of water in osmosis. A semipermeable membrane is placed between the following solutions. Which solution will increase in volume? Solution C: 9% (m/v) NaCl Solution D: 12.4% (m/v) NaCl

Solution D: 12.4% (m/v) NaCl

When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur? The cell will burst The cell membrane will lyse Plasmolysis will shrink the interior The cell will become flaccid The cell will become turgid

The cell will become turgid

Red blood cells contain approximately a 2% concentration of solutes. A red blood cell is placed into a solution that contains a 4% concentration of solutes to which the cell is not permeable. What will happen to the red blood cell? Nothing will happen because the solution and the cell are isotonic to each other. The cell will increase in size as water flows into it. The solutes will diffuse into the cell. The cell will decrease in size as water flows out of it. The solutes will diffuse out of the cell.

The cell will decrease in size as water flows out of it.

Celery stalks that are immersed in fresh water for several hours become stiff. Which of the following statements best explains the observation that similar stalks left in a 0.15 M salt solution become limp? The fresh water is hypotonic and the salt solution is hypertonic to the cells of the celery stalks The fresh water is hypertonic and the salt solution is hypotonic to the cells of the celery stalks The fresh water is isotonic and the salt solution is hypertonic to the cells of the celery stalks The fresh water and the salt solution are both hypertonic to the cells of the celery stalks

The fresh water is hypotonic and the salt solution is hypertonic to the cells of the celery stalks

Which of the following statements best explains how the membranes in winter wheat are able to remain fluid in extremely cold temperatures? The membranes contain an increased proportion of glycolipids. The membranes contain an increased proportion of unsaturated phospholipids. The membranes contain a reduced proportion of cholesterol molecules. The membranes contain a reduced proportion of hydrophobic proteins.

The membranes contain an increased proportion of unsaturated phospholipids.

A cell is placed into a solution and the cell shrinks. Which of the following is true regarding the solution? None of the listed responses is correct. The solution has the same solute concentration as the cell. The solution is hypotonic. The solution is hypertonic. The cell is hypertonic.

The solution is hypertonic.

1.5 M glucose, 1.5 M glucose

The solutions in the two arms of a 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 2 M sucrose and 1 M glucose. Side B is half-filled with 1 M sucrose and 2 M glucose. 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 ________. 1.5 M glucose, 1.5 M glucose 2 M sucrose, 1 M glucose 1 M sucrose, 2 M glucose 2 M sucrose, 2 M sucrose

The water level will be higher in side A than in side B.

The solutions in the two arms of a 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 2 M sucrose and 1 M 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 is the most likely result when the system has reached equilibrium? The water levels will be unchanged. The concentration of sucrose on side A will be greater than the concentration of sucrose on side B. The water level will be higher in side A than in side B. The water level will be higher in side B than in side A.

side A is isotonic to side B

The solutions in the two arms of a 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 2 M sucrose and 1 M 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 statements best describes the relationship between the solutions on both sides of the U-tube? side A is hypotonic to side B side A is more turgid than side B side A is hypertonic to side B side A is isotonic to side B

Which of the following is correct regarding peripheral proteins? These proteins are found only on the surface of the plasma membrane. These proteins exhibit both hydrophilic and hydrophobic properties. They exhibit only hydrophobic properties. They have no specific function in the plasma membrane. They span the entire phospholipid bilayer.

These proteins are found only on the surface of the plasma membrane.

Which of the following is correct regarding integral proteins? They exhibit only hydrophobic properties. These proteins exhibit both hydrophilic and hydrophobic properties. They have no specific function in the plasma membrane. These proteins are found only on the surface of the plasma membrane. They exhibit only hydrophilic properties.

These proteins exhibit both hydrophilic and hydrophobic properties.

Which of the following statements best describes a characteristic feature of integral membrane proteins? They are hydrophobic. They are amphipathic, with at least one hydrophobic region. They are hydrophilic. They are localized to the interior surface of the membrane.

They are amphipathic, with at least one hydrophobic region.

According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids? They can move laterally along the plane of the membrane. They frequently flip-flop from one side of the membrane to the other. They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane. They are free to depart from the membrane and dissolve in the surrounding solution. They have hydrophilic tails in the interior of the membrane.

They can move laterally along the plane of the membrane.

Hypertonic

This cell is in a(n) _____ solution.

In the kidneys, water moves by osmosis from tubules called nephrons to the bloodstream. Do you expect a nephron to be hypotonic, isotonic, or hypertonic relative to the blood?

You would expect the nephrons to be hypotonic compared to the blood.

Which of the following factors would tend to increase membrane fluidity? a greater proportion of saturated phospholipids a lower temperature a greater proportion of unsaturated phospholipids a relatively high protein content in the membrane

a greater proportion of unsaturated phospholipids

If the concentration of phosphate in the cytosol is 2.0 mM, and the concentration of phosphate in the surrounding fluid is 0.1 mM, how could the cell increase the concentration of phosphate in the cytosol? facilitated diffusion diffusion active transport passive transport osmosis

active transport

Active and passive transport of solutes across a membrane typically differ in which of the following ways? active transport is always faster than passive transport Active transport is used for ions, whereas passive transport is used for uncharged solutes. active transport is usually down the concentration gradient of the solute, whereas passive transport is always against the concentration gradient of the solute active transport always involves the utilization of cellular energy, whereas passive transport does not require cellular energy active transport uses protein carriers, whereas passive transport uses carbohydrate carriers

active transport always involves the utilization of cellular energy, whereas passive transport does not require cellular energy

In facilitated diffusion, __________ proteins provide openings in the plasma membrane for substances to flow through without changing structure, and __________ proteins allow passage of substances through the plasma membrane after undergoing a subtle change in shape. peripheral; enzymatic receptor; channel active transport; signal transduction carrier; channel channel; carrier

channel; carrier

Phospholipids vary in the small molecules attached to the phosphate group. The phospholipid shown in the figure has a _______ attached to phosphate.

choline group

Endocytosis moves materials _____ a cell via _____. out of ... membranous vesicles into ... facilitated diffusion into ... a transport protein out of ... diffusion into ... membranous vesicles

into ... membranous vesicles

All cells have voltages across their membranes. This voltage is called a(n) __________ and is often maintained by __________. concentration gradient; osmosis membrane potential; electrogenic pumps None of the listed responses is correct. electrochemical gradient; diffusion iotonic solution; diffusion

membrane potential; electrogenic pumps

What name is given to the process by which water crosses a selectively permeable membrane? passive transport phagocytosis osmosis diffusion pinocytosis

osmosis

To prevent crenation of hemolysis, a cell must be placed in an isotonic solution such as 0.9% (m/v) NaCl or 5.0% (m/v) glucose. This does not mean that the cell has a 5.0% (m/v) glucose concentration, it just means the 5.0% (m/v) glucose will exert the same ______________ as the the solution inside the cell, which contains several different solutes.

osmotic pressure

Turgor Pressure

pertains to the pressure that is exerted by the fluid (e.g. water) against the cell wall.

A white blood cell engulfing a bacterium is an example of _____. phagocytosis pinocytosis facilitated diffusion exocytosis receptor-mediated endocytosis

phagocytosis

The plasma membrane exhibits selective permeability. This means that __________. the plasma membrane allows any substance to flow through it easily proteins in the membrane do not affect its permeability the plasma membrane allows some substances to flow through it more easily than others the plasma membrane does not allow any substance to flow through it the structure of the plasma membrane does not affect its permeability

the plasma membrane allows some substances to flow through it more easily than others

The sodium-potassium pump __________. does not require energy to function transports sodium ions out of the cell transports glucose into the cell transports potassium ions into the cell transports sodium ions out of the cell and transports potassium ions into the cell

transports sodium ions out of the cell and transports potassium ions into the cell