Question 1

Phospholipids spontaneously form a bilayer in an aqueous solution. Why do the heads of the phospholipids point out and the tails point toward one another?

Accepted Answer

A)   The tails are nonpolar and form hydrogen bonds with one another.
B)   The heads are repelled by the water inside and outside the cell.
C)   The tails are repelled by the aqueous environment, and the heads will directly interact with the aqueous solution.

Question 2

Imagine that beaker A has a 10% sucrose solution, and beaker B has an 8% sucrose solution. This means that

Accepted Answer

A)   beaker A is isotonic relative to beaker B.
B)   beaker A is hypotonic relative to beaker B.
C)   beaker A is hypertonic relative to beaker B.

Question 3

is used by white blood cells to consume large particles such as bacteria.

Accepted Answer

The answer of is used by white blood cells to...

Question 4

According to the fluid mosaic model of cell membranes, which of the following is a TRUE statement about membrane phospholipids?

Accepted Answer

A)   They frequently flip- flop from one side of the membrane to the other.
B)   They form a viscous fluid through which proteins shift and flow.
C)   They have hydrophilic tails in the interior of the membrane.
D)   They occur in an uninterrupted bilayer, with membrane proteins strictly anchored to the surface of the membrane.
E)   They are free to depart from the membrane and are dissolved in the surrounding solution.

Question 5

The secretion of excess water via a contractile vesicle of a Paramecium cell is an example of

Accepted Answer

A)   active transport.
B)   osmosis.
C)   simple diffusion.
D)   exocytosis.
E)   facilitated diffusion.

Question 6

Which of the following is an energy- requiring mode of transport that brings substances into a cell?

Accepted Answer

A)   Osmosis
B)   Simple diffusion
C)   Active transport
D)   Facilitated diffusion

Question 7

Imagine an artificial cell made with a selectively permeable membrane that allows water to pass through but does not allow sugar to pass. If the artificial cell contains a 1% sugar solution and then you place the cell in a 2% sugar solution, what happens?

Accepted Answer

A)   There is no movement of water.
B)   Water leaves the cell because the solution is hypertonic to the cell.
C)   Sugar diffuses in and water diffuses out until equilibrium is reached.
D)   Water enters the cell because the solution is hypotonic to the cell.

Question 8

ISO membranes are inside- out membrane vesicles used by researchers in membrane studies. As a molecule diffuses into the vesicle, it will encounter the layers of the membrane in the following order

Accepted Answer

A)   tail- head- head- tail.
B)   head- tail- head- tail.
C)   tail- head- tail- head.
D)   head- tail- tail- head.
E)   head- head- tail- tail.

Question 9

Carbon dioxide crosses the plasma membrane by simple diffusion. The rate at which carbon dioxide enters the cell is determined by the

Accepted Answer

A)   amount of energy being produced by the cell.
B)   amount of transport protein in the membrane.
C)   concentration of carbon dioxide on each side of the membrane.
D)   amount of oxygen being exported from the cell.
E)   amount of carbon dioxide outside of the cell.

Question 10

The rate of facilitated diffusion of a molecule across a membrane will increase as the concentration gradient of the molecule across the membrane increases to a certain point. Eventually, an increase in the concentration of the molecule will not cause any further increase in facilitated diffusion. Thus, there is a maximal rate of facilitated diffusion. This is because

Accepted Answer

A)   the diffusion constant depends on the concentration gradient.
B)   the increased concentration gradient causes a situation far from equilibrium.
C)   there are a limited number of carrier proteins in the membrane.
D)   as the concentration gradient increases, molecules interfere with one another.
E)   facilitated diffusion requires ATP energy.

Question 11

In reference to diffusion, passive really means

Accepted Answer

A)   in the air.
B)   very slowly.
C)   no gradient.
D)   without a membrane.
E)   no energy required.

Question 12

Recognition proteins, such as those embedded on the surface of red blood cells, are composed of

Accepted Answer

A)   glycoproteins.
B)   phospholipases.
C)   nucleic acids.
D)   steroids.

Question 13

A freshwater protozoan, such as Paramecium, tends to because it lives in a environment.

Accepted Answer

A)   lose water; hypertonic
B)   gain water; isotonic
C)   lose water; hypotonic
D)   gain water; hypotonic
E)   gain water; hypertonic

Question 14

What happens when diffusion moves molecules across the plasma membrane?

Accepted Answer

A)   The process is relatively slow and is driven by concentration gradients.
B)   Most molecules are capable of crossing the phospholipid bilayer at any location and at basically the same rate.
C)   The cell gains needed materials and gets rid of excess materials very quickly.
D)   The rate of diffusion cannot be influenced by the cell.
E)   Energy input is required to transport molecules.

Question 15

Suppose a bag made of a selectively permeable membrane was filled with a 5% solution of glucose and sealed. What would happen if the bag was placed in pure water or in a 10% glucose solution?

Accepted Answer

In pure water, the bag would s...

Question 16

What is active transport?

Accepted Answer

A)   Movement of molecules into or out of a cell down a concentration gradient
B)   Rapid movement of molecules in a solution
C)   Movement of molecules into or out of a cell against a concentration gradient
D)   Movement of molecules into or out of a cell using special proteins and not requiring an expenditure of energy
E)   Diffusion of molecules within a cell

Question 17

The net movement of molecules from a high concentration to a low concentration is best described by which of the following?

Accepted Answer

A)   Endocytosis
B)   Exocytosis
C)   Osmosis
D)   Active transport
E)   Passive transport

Question 18

If the radius of one cell were twice as large as the radius of another cell, how much higher or lower would its surface- area- to- volume ratio be?

Accepted Answer

A)   2 times lower
B)   2 times higher
C)   1/2 lower
D)   10 times higher

Question 19

Glucose is a six- carbon sugar that diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose- rich food into their glucose- poor cytoplasm. Given this information, which transport mechanism is most probably functioning in the intestinal cells?

Accepted Answer

A)   Simple diffusion
B)   Osmosis
C)   Exocytosis
D)   Aquaporin transport
E)   Facilitated diffusion

Question 20

The electrical signal for a muscle to contract passes rapidly from one cell to the next via

Accepted Answer

A)   gap junctions.
B)   desmosomes.
C)   plasmodesmata.
D)   tight junctions.
E)   internal proteins.

Exam 5: Cell Membrane Structure and Function

Recognition proteins, such as those embedded on the surface of red blood cells, are composed of

Correct Answer
verified

Which of the following is an energy- requiring mode of transport that brings substances into a cell?

Correct Answer
verified

Correct Answer
verified

Imagine that beaker A has a 10% sucrose solution, and beaker B has an 8% sucrose solution. This means that

Correct Answer
verified

If the radius of one cell were twice as large as the radius of another cell, how much higher or lower would its surface- area- to- volume ratio be?

Correct Answer
verified

Imagine an artificial cell made with a selectively permeable membrane that allows water to pass through but does not allow sugar to pass. If the artificial cell contains a 1% sugar solution and then you place the cell in a 2% sugar solution, what happens?

Correct Answer
verified

Carbon dioxide crosses the plasma membrane by simple diffusion. The rate at which carbon dioxide enters the cell is determined by the

Correct Answer
verified

is used by white blood cells to consume large particles such as bacteria.

Correct Answer
verified

Suppose a bag made of a selectively permeable membrane was filled with a 5% solution of glucose and sealed. What would happen if the bag was placed in pure water or in a 10% glucose solution?

Correct Answer
verified
In pure water, the bag would s...
View Answer

Correct Answer
verified

A freshwater protozoan, such as Paramecium, tends to because it lives in a environment.

Correct Answer
verified

The electrical signal for a muscle to contract passes rapidly from one cell to the next via

Correct Answer
verified

What is active transport?

Correct Answer
verified

The secretion of excess water via a contractile vesicle of a Paramecium cell is an example of

Correct Answer
verified

According to the fluid mosaic model of cell membranes, which of the following is a TRUE statement about membrane phospholipids?

Correct Answer
verified

The net movement of molecules from a high concentration to a low concentration is best described by which of the following?

Correct Answer
verified

In reference to diffusion, passive really means

Correct Answer
verified

What happens when diffusion moves molecules across the plasma membrane?

Correct Answer
verified

ISO membranes are inside- out membrane vesicles used by researchers in membrane studies. As a molecule diffuses into the vesicle, it will encounter the layers of the membrane in the following order

Correct Answer
verified

Phospholipids spontaneously form a bilayer in an aqueous solution. Why do the heads of the phospholipids point out and the tails point toward one another?

Correct Answer
verified

Exam 5: Cell Membrane Structure and Function

Recognition proteins, such as those embedded on the surface of red blood cells, are composed of

Correct AnswerverifiedShow Answer

Which of the following is an energy- requiring mode of transport that brings substances into a cell?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Imagine that beaker A has a 10% sucrose solution, and beaker B has an 8% sucrose solution. This means that

Correct AnswerverifiedShow Answer

If the radius of one cell were twice as large as the radius of another cell, how much higher or lower would its surface- area- to- volume ratio be?

Correct AnswerverifiedShow Answer

Imagine an artificial cell made with a selectively permeable membrane that allows water to pass through but does not allow sugar to pass. If the artificial cell contains a 1% sugar solution and then you place the cell in a 2% sugar solution, what happens?

Correct AnswerverifiedShow Answer

Carbon dioxide crosses the plasma membrane by simple diffusion. The rate at which carbon dioxide enters the cell is determined by the

Correct AnswerverifiedShow Answer

is used by white blood cells to consume large particles such as bacteria.

Correct AnswerverifiedShow Answer

Suppose a bag made of a selectively permeable membrane was filled with a 5% solution of glucose and sealed. What would happen if the bag was placed in pure water or in a 10% glucose solution?

Correct AnswerverifiedIn pure water, the bag would s...View AnswerShow Answer

Correct AnswerverifiedShow Answer

A freshwater protozoan, such as Paramecium, tends to because it lives in a environment.

Correct AnswerverifiedShow Answer

The electrical signal for a muscle to contract passes rapidly from one cell to the next via

Correct AnswerverifiedShow Answer

What is active transport?

Correct AnswerverifiedShow Answer

The secretion of excess water via a contractile vesicle of a Paramecium cell is an example of

Correct AnswerverifiedShow Answer

According to the fluid mosaic model of cell membranes, which of the following is a TRUE statement about membrane phospholipids?

Correct AnswerverifiedShow Answer

The net movement of molecules from a high concentration to a low concentration is best described by which of the following?

Correct AnswerverifiedShow Answer

In reference to diffusion, passive really means

Correct AnswerverifiedShow Answer

What happens when diffusion moves molecules across the plasma membrane?

Correct AnswerverifiedShow Answer

ISO membranes are inside- out membrane vesicles used by researchers in membrane studies. As a molecule diffuses into the vesicle, it will encounter the layers of the membrane in the following order

Correct AnswerverifiedShow Answer

Phospholipids spontaneously form a bilayer in an aqueous solution. Why do the heads of the phospholipids point out and the tails point toward one another?

Correct AnswerverifiedShow Answer

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verified
In pure water, the bag would s...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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