web viewsection 7.3 cell transportname: biology. ... the movement of materials across the cell...

Section 7.3 Cell Transport Name: Biology Date: Period:

Lesson SummaryPassive Transport The movement of materials across the cell membrane without using cellular energy is called passive transport. Diffusion is the process by which particles move from an area of high concentration to an area of lower

concentration. Facilitated diffusion is the process by which molecules that cannot directly diffuse across the membrane

pass through special protein channels. Osmosis is the facilitated diffusion of water through a selectively permeable membrane.

Aquaporins Isotonic

Hypertonic Hypotonic

Osmotic pressure is the force caused by the net movement of water by osmosis.

Active Transport is the movement of materials against a concentration difference that requires energy. Transport proteins that act like pumps use energy to move small molecules and ions across cell

membranes. The bulk transport of large molecules and clumps of materials into and out of cells occurs by

movements of the cell membrane, which require energy.

Passive TransportFor Questions 1–4, write the letter of the correct answer on the line at the left._____ 1. Which of the following must be true for diffusion to occur?

A. Molecules or particles must have different sizes.B. Special protein channels must always be available.C. There must be areas of different concentrations.D. Energy must be available.

_____ 2. Which term refers to the condition that exists when no net change in concentration results from diffusion?A. concentrationB. osmosis

C. equilibriumD. randomness

_____ 3. Air has a higher concentration of oxygen molecules than does the cytoplasm of your lung cells. Where in your lungs will there be a net increase of oxygen?A. in the air breathed inB. outside of the lung cells

C. in the air breathed outD. inside of the lung cell

_____ 4. Which of the following statements tells how facilitated diffusion differs from simple diffusion?A. Particles move through cell membranes without the use of energy by cells.B. Particles tend to move from high concentration to lower concentration.C. Particles move within channel proteins that pass through cell membranes.D. Particles tend to move more slowly than they would be expected to move.

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Match the situation with the result. Write the letter of the correct answer on the line at the left.

Situation_____ 5. Cells are in an isotonic solution._____ 6. Cells are in a hypertonic solution._____ 7. Cells are in a hypotonic solution.

ResultA. The cells lose water.B. The cells gain water.C. The cells stay the same.

8. In the table below, draw how each type of cell will look after being placed in a hypertonic solution.

Appearance of Cells in a Hypertonic Solution

Animal Cells Plant Cells

Passive Transport

Diffusion is the movement of particles from an area of high concentration to an area of low concentration. Osmosis is the diffusion of water through a selectively permeable membrane. Study the beakers at the right. The arrows between beakers tell you what process is occurring.9. In the beakers on the right, draw the result of the

described process. Draw changes in water levels. Draw changes in the number of solute particles. Remember to draw on both sides of the membrane.

10. Look at the top left beaker. What would happen if the membrane did not allow water or solute particles to pass through it?

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Label each diagram as either facilitated diffusion or active transport.

Facilitated diffusion takes place when a substance diffuses across the cell membrane through a protein channel.

Active transport takes place when the cell uses energy to carry a substance across the cell membrane against a concentration difference.

Answer the questions by circling the correct answer.1. Which process can move molecules

from a lower concentration solution on one side of the membrane to a higher concentration solution on the other side?

active transportfacilitated diffusion

2. Which process does not require energy?

active transport facilitated diffusion

3. What does the word facilitated mean in facilitated diffusion?hindered helped

Active Transport11.What is the function of active transport in moving small molecules and ions across cell membranes? Give

an example.

12. How does ATP enable transport proteins to move ions across a cell membrane?

13. What are the proteins used in active transport called?

Moleculebeing carried

Energy

Molecule tobe carried

Glucose molecules

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14. Complete the table to summarize the types of bulk transport.

Types of Bulk Transport

Type Description

Endocytosis

Phagocytosis

Exocytosis

15. Compare/Contrast Table Use a compare/contrast table when you want to see the similarities and differences between two or more objects or processes. Select words or phrases from the box to complete the table comparing passive and active transport.

Passive Transport Active Transport

16. Most sports drinks are isotonic in relation to human body fluids. Explain why athletes should drink solutions that are isotonic to body fluids when they exercise rather than ones that are hypotonic to body fluids (contain a greater proportion of water in comparison to the fluids in and around human body cells).

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diffusion energy required exocytosis osmosis endocytosis energy not required facilitated diffusion protein pumps

Diffusion and Osmosis Problems Name: Biology 6.0 Date: Period:

1. Use the diagram to answer questions a, b, and c.

Beaker A Beaker B Beaker C 100 % Water ____% Sugar 40% Sugar

90% Water ___% Water

a. What is the solute concentration of Beaker A? b. Beaker B?

c. What is the solvent concentration of Beaker C?

2. For each of the following, determine the % concentration of the solute and the solvent for the solution outside the cell (environment) and for the inside of the cell. A. Tell whether the solution outside the cell is hypotonic, hypertonic, or isotonic.B. Give the direction of the net movement of water (into cell, out of cell, into & out of cell at equal rates).C. Tell what will happen to the cell (shrink, swell or stay the same).

a.

b.

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80 % solute___ % solvent


C.

B.

A.

___ % solute90 % solvent


C.

B.

A.

c.

d.

e.

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C.

B.

A.

C.

B.

A.

C.

B.

A.





3. Use the diagram to the right of a cell submerged in a solution. The membrane is permeable to water but not to sugar.

a. What is the solution in this example?

hypotonic hypertonic isotonic

b. How do you know?

c. What process is going to take place in this example?

diffusion osmosis

d. Describe exactly what is going to happen to the cell in this example.

4. The cell in this beaker is bathed in a 5% saline (NaCl) solution. The membrane is permeable to water but not to NaCl.

a. In which direction is the net movement of water here?

b. How will this affect the cell?

5. The solutions in the arms of the U-tube (at right) are separated by a selectively permeable membrane that is permeable to water and solute A, but not to solute B. 40 g of solute A and 20 g of solute B have been added to the water on side 1 of the U-tube. 20 g of solute A and 40 g of solute B have been added to the water on side 2 of the U-tube. Assume that after a period of time, equilibrium is reached. a. How many grams of solute A will be in solution on side 1 and side 2 of the U-

tube? Explain.

b. How many grams of solute B will be in solution on side 1 and side 2 of the U-tube? Explain.

c. What has happened to the water level in the U-tube? Explain your answer.

6. In the U-tube diagram, the membrane is permeable to water and solute A but it is NOT permeable to solute Z.a. What is going to happen to solute A (both direction and percentages)?

b. What is going to happen to solute Z (both direction and percentages)?

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0.9% NaCl

5% NaCl

30% Sugar___% Water

70% Sugar___% Water

Side 1 Side 2

Side 120% A10% Z

Side 26% A40% Z

c. What is going to happen to the water levels, specifically?7. A U-tube is divided into 2 halves, side 1 and 2, by a membrane which is permeable to water and salt, but

NOT to glucose. Side A is filled with a solution of 8% salt and 2% glucose, while side B is filled with 2% salt and 8% glucose.

a. What could you say about the water concentration on side 1 relative to side 2?

b. Which molecule(s) will move across the membrane and in which net direction(s)?

c. Notice that the levels of liquid in both A and B are equal. Do you think they will appear this way when the system reaches equilibrium? Explain.

8. Three funnels containing three different starch solutions were placed for 24 hours into a beaker that contained a starch solution of UNKNOWN concentration. The end of each funnel was covered by a selectively permeable membrane allowing only water to pass across the membrane.

Based on the results, what is the concentration of the unknown solution? How can you tell?

9. Flasks X, Y, and Z contain solutions with different concentrations of the solute NaCl. Flask X has 0.5% NaCl, flask Y has 0.9% NaCl, and flask Z has 1.5% NaCl. Red blood cells (0.9% NaCl) will be placed into each flask. Predict what will happen when water crosses the red blood cell membrane.

a. Predict what will happen to the red blood cells in flask X (draw a diagram).

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Side 1 Side 2

UNKNOWN Solution

2% Starch Solution

4% Starch SolutionSelectively

Permeable Membrane

Tap Water

AFTER 24 HOURS

C A B C

b. Predict what will happen to the red blood cells in flask Y (draw a diagram).

c. Predict what will happen to the red blood cells in flask Z (draw a diagram).

10. Study the diagrams of the beakers to the right, noting the concentrations of various substances in the beakers and in the cellulose bags. Water molecules can pass through the cellulose, but starch cannot pass through.

a. Draw arrows in the diagrams to show the direction in which water will move.

b. Which of the beakers contains a solution that is hypertonic relative to the bag’s contents?

c. What will eventually happen to the concentrations in beaker 2?

11. Intravenous solutions must be prepared so that they are isotonic to red blood cells. A 0.9% salt solution is isotonic to red blood cells.

a. Explain what will happen to a red blood cell placed in a solution of 99.3% water and 0.7% salt.

b. What will happen to a red blood cell placed in a solution of 90% water and 10% salt?

Review: 12. What is turgor pressure in a plant cell?

13. What keeps plants cells from bursting when they are placed in a hypotonic solution?

14. How does being placed in a hypertonic solution affect a plant cell?

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90% Water10% Starch

90% Water10% Starch

100% Water 80% Water20% Starch

1 2

15. In regard to the solutions in the bags and in the beakers, what is meant by equilibrium?

16. What happens to the motion of molecules after equilibrium is reached?

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CELLULAR TRANSPORT REVIEW Name: ______________________________

Biology Date: _______________ Period: _____

Label the following:

1. The process of diffusion causes molecules to move from (low to high or high to low) concentrations until a state of ____________________ is reached.

2. The diffusion of water is known as __________________.

3. ________________ diffusion uses proteins to bring materials into the cell from high to low concentration, requiring no cell energy.

4. Diffusion, osmosis and facilitated diffusion are all examples of _____________ transport, in which the cell does not need to use any energy.

5. During active transport molecules move from an area of ___________ concentration to an area of ____________ concentration.

6. ________________ is a form of active transport in which the cell sends materials out of the cell using vesicles, small storage structures that fuse to the cell membrane.

7. _________________ is the reverse of the process named in # 6. The cell membrane wraps around a substance to be brought into the cell forming a vesicle around it.

8. There are two types of endocytosis: __________________ which involves bringing solids or large molecules into the cell, and _________________, which deals with bringing liquids or very small molecules into the cell.

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B.

E.

D.

F.

A.

G.

C.

B.

9. In the pictures below each “X” represents a molecule of water. In each diagram indicate which direction water will be moving (mostly in, mostly out, or equally in and out).

A. B. C.

10. Look at each of the pictures below. Identify whether the picture represents a plant cell in fresh water or salt water.

A. B.

Multiple Choice:1. The substance that dissolves to make a solution is called the ___________________

A. diffuserB. solvent

C. soluteD. concentrate

2. During diffusion molecules tend to move _____________________A. up the concentration gradientB. down the concentration gradientC. from an area of lower concentration to an area of higher concentrationD. in a direction that doesn’t depend on concentration

3. When the concentration of a solute is the same throughout a system, the system has reached ____________.A. maximum concentrationB. homeostasis

C. osmotic pressureD. equilibrium

4. The diffusion of water across a selectively permeable membrane is called ________________.A. active transportB. facilitated diffusion

C. osmosisD. phagocytosis

5. Phagocytosis, pinocytosis, and exocytosis are all kinds of _______________ transport.A. active B. passive

6. Glucose enters cells most rapidly by _________________A. diffusionB. facilitated diffusion

C. ion channelsD. phagocytosis

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XXXXX XXXXX XXXXXXX XXXXX XXXXXXXXXX

7. ________________ transport requires energy from ATP to move substances across membranes.A. Active B. Passive

8. A cell must expend energy to transport substances using ________________.A. diffusionB. facilitated diffusionC. ion channels

D. osmosisE. endocytosis

9. White blood cells engulf, digest, and destroy invading bacteria using __________________.A. Facilitated diffusion B. pinocytosis

C. phagocytosisD. osmosis

10. All of the following are kinds of passive transport EXCEPT ________________________A. diffusionB. facilitated diffusion

C. osmosisD. phagocytosis

11. Endocytosis that brings in small dissolved molecules (solutes) and fluids is called ___________________.A. pinocytosisB. phagocytosis

C. facilitated diffusionD. osmosis

12. Placing an animal cell in a hypotonic solution will cause water to ______________________.A. move into the cell B. move out of the cell

13. When molecules move DOWN the concentration gradient it means they are moving from ______________A. an area of low concentration to an area of higher concentrationB. an area of high concentration to an area of lower concentration

14. Gases like oxygen and carbon dioxide move across cell membranes using _____________________A. EndocytosisB. ion channels

C. diffusionD. facilitated diffusion

LOOK AT THE DIAGRAMS. The black dots represent solute molecules dissolved in water.

15. In which beaker is the concentration of solute the greatest?

A or B

16. If the solute (dots) in this diagram is unable to pass through the dividing membrane, what will happen?A. the water level will rise on the right side of the tubeB. the water level will rise on the left side of the tubeC. the water level will stay equal on the two sides

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A B

17. Label the pictures below (isotonic, hypertonic, or hypotonic)

A. _________________ B. __________________ C. _________________

18. _____________tonic means there is a GREATER concentration of solute molecules OUTSIDE the cell than inside.

19. _____________tonic means there is a LOWER concentration of solute molecules OUTSIDE the cell than inside.

20. _____________tonic means there is the SAME concentration of solute molecules outside the cell as inside.

COMPARE/CONTRAST the kinds of transport

Activeor

Passive

What does it use to help? Carrier proteins?

Vesicles?Needs no help?

Example of substance(s) that use this kind of

transport in cells

DIFFUSION

FACILITATEDDIFFUSION

OSMOSIS

ENDOCYTOSIS(phagocytosis)

ENDOCYTOSIS(pinocytosis)

EXOCYTOSIS Any substance leaving cells

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A Look at Cell TransportBiology Keystone Constructed Response

Examine the diagram below. The letters represent molecules. The relative size of the molecules is represented by the size of the letter. The concentrations of molecules on each side of the membrane can be determined by the numbers of each letter on each side of the membrane. Arrows show the direction the molecules travel as they cross the membrane.

1. What type of transport is demonstrated by molecule a? Explain how you know. Include anything else that you know about this process.

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

2. What type of transport is demonstrated by molecule B? Explain how you know. Include anything else that you know about this process.

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

3. What type of transport is demonstrated by molecule C? Explain in detail how molecule C could cross the

membrane.

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________

_______________________________________________________________________________________16

The diagram below shows molecules represented by X both outside and inside of a cell.

1. A process that would result in the movement of these molecules out of a cell requires the use ofA. DNA B. ATP C. antigens D. antibodies

Use the diagram on the right to answer questions 2 and 3. Starch turns blue black in the presence of a starch indicator such as iodine. Dialysis tubing tied at both ends and containing starch solution is placed in a beaker of water. The yellowish brown starch indicator (iodine) is then added to the water. The dialysis tubing allows iodine to pass through but not starch.

2. What will the solutions in the beaker and the tubing look like after 20 minutes?A. The indicator solution in the beaker will be blue black and the starch solution in the tubing will not

change color.B. The starch solution in the tubing will be blue black and the indicator solution in the beaker will not

change color.C. Neither the indicator solution nor the starch solution will be blue black.D. Both the indicator solution and the starch solution will be blue black.

3. This laboratory setup would most likely be used to demonstrate the process ofA. diffusion C. replicationB. active transport D. cellular respiration

4. Two molecules, A and B and their distribution inside and outside of a cell are represented in the diagram to the right. State one possible reason why molecule A could diffuse across the membrane of the cell but molecule B could not.

5. Some animals can produce a potassium ion concentration inside their cells that is 20 times greater than that of their environment. The ion concentration gradient is maintained by the plasma membrane. Explain the process that occurs as the cell produces the ion concentration gradient.

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CELL TRANSPORT REVIEW 2 Name:

Biology 6.0 Date: Period:

1. The fluid mosaic model describes the plasma membrane as consisting of a. a phospholipid bilayer with embedded carbohydrates.b. two layers of phospholipids with proteins sandwiched between them.c. a protein bilayer with embedded phospholipids.d. carbohydrates, proteins, and phospholipids that can drift in the membrane.e. a phospholipid bilayer embedded with proteins attached to carbohydrates that can “float” among the lipids.

2. Membrane phospholipidsa. have hydrophobic heads that face the center of the membrane and are shielded from water.b. often have “kinks” in their tails caused by the presence of a double bond between carbons.c. form a strong barrier between the cell and its surroundings.d. form impermeable layers for cells.

3. Most of the functions of a cell membrane are performed by

a. glycolipids.b. proteins.c. phospholipids.

d. cholesterol.e. nucleotides.

4. Oxygen crosses a plasma membrane by

a. osmosis.b. phagocytosis.c. active transport.

d. pinocytosis.e. passive transport.

5. Plasma membranes are selectively permeable. This means thata. anything can pass into or out of a cell as long as the membrane is intact and the cell is healthy.b. the plasma membrane allows some substances to enter of leave a cell more easily than others.c. glucose cannot enter the cell.d. cholesterol cannot enter the cell.e. plasma membranes must be very thick.

6. Small, nonpolar, hydrophobic molecules such as fatty acidsa. easily pass through a membrane’s lipid bilayer.b. very slowly diffuse through a membrane’s lipid bilayer.c. require transport proteins to pass through a membrane’s lipid bilayer.d. are actively transported across cell membranes.e. usually enter the cell via endocytosis.

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7. Facilitated diffusion across a biological membrane requires _______ and moves a substance _______ its concentration gradient.

a. energy/transport proteins…….downb. energy down….. downc. transport proteins….. down

d. energy/transport proteins…..againste. transport proteins…..against

8. In the lab, you use a special balloon that is permeable to water but not sucrose to make an “artificial” cell. The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. The solution in the beaker is ___________ relative to the solution in the balloon.

a. isotonic b. hypertonic c. hypotonic

9. Which of the following will occur?

a. Water will enter the balloon.b. Water will leave the balloon.

c. Nothing will occur.d. Water will enter and leave the balloon.

10. Which of the following statements regarding diffusion is false?a. It is a result of kinetic energy of atoms and molecules.b. It is driven by concentration gradients.c. It requires no input of energy into the system.d. It occurs when particles spread from areas where they are less concentrated to areas where they are more

concentrated.e. It occurs even after equilibrium is reached an not net change is apparent.

11. The diagram to the right represents a portion of a cell membrane. Which structure represents a hydrophobic region?

a. Space between phospholipidsb. Proteinc. Phosphate headd. Fatty acid tails

12. Diffusion does not require the cell to expend any ATP. Therefore, diffusion is considered a type of

a. exocytosis.b. phagocytosis.c. passive transport.

d. active transport.e. endocytosis.

13. Which of the following processes could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than in its surroundings?

a. Active transportb. Facilitated diffusionc. Diffusion

d. Osmosise. Passive transport

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14. When physicians perform an organ transplant, they choose a donor whose tissues match those of the recipient as closely as possible. Which of the following cell components are being matched?

a. Plasma membrane phospholipidsb. Plasma membrane proteinsc. Cell-surface carbohydrates

d. Plasma membrane cholesterolse. Cytoskeletal elements

15. The diagram to the right shows the relative concentration of molecules inside and outside of a cell. Which statement best describes the general direction of diffusion across the membrane of this cell? a. Glucose would diffuse into the cell.b. Protein would diffuse out of the cell.c. Carbon dioxide would diffuse out of the celld. Oxygen would diffuse into the cell.

16. In a hypotonic solution, an animal cell will

a. lyse.b. experience turgor .c. neither gain nor lose water.

d. shrivel.e. lose water.

17. You are adrift in the Atlantic Ocean, and, being thirsty, drink the surrounding seawater. As a result,

a. you quench your thirst.b. your cells lyse due to the excessive intake of salts.c. your cells become turgid.

d. you dehydrate yourself.e. your cells lyse from excessive water intake.

18. The diagram below represents movement of a large molecule across a membrane. Which process is best represented by this diagram? a. Active transportb. Diffusionc. Osmosisd. Protein building

19. The diagram on the right represents a cell in water. Formulas of molecules that can move freely across the cell membrane are shown. Some molecules are located inside the cell and others are in the water outside the cell. Based on the distribution of these molecules, what would most likely happen after a period of time?a. The concentration of O2 will increase inside the cell. b. The concentration of CO2 will remain the same inside the cell.c. The concentration of O2 will remain the same outside the cell.d. The concentration of CO2 will decrease outside the cell.

20. White blood cells are more resistant to lysis than red blood cells. When looking at a sample of blood for WBCs what could you do to reduce interference from RBCs?a. Mix the blood in a salty solution to cause the RBC’s to lyse.

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b. Mix the blood in an isotonic solution and allow the WBCs to float to the top.c. Mix the blood with a dye that stains the proteins in the cytoplasm.d. Mix the blood with a hypotonic solution, which will cause the RBCs to lyse.e. Mix the blood with a hypertonic solution, which will cause the RBCs to lyse.

21. Activities in the human body are represented in the diagram to right. Which would be appropriate for the diagram? a. Rate of excretion varies in response to amount of water taken inb. Feedback mechanisms help to maintain homeostasisc. Respiratory rate responds to an increase in muscle activityd. The nervous system responds to changes in blood sugar levels

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22. The function of the white blood cells in your body is to find and digest invading bacteria cells. The diagram below shows how the white blood cells ingest the invading bacteria cells. Name and explain the process.

23. Paramecium is a single celled eukaryotic organism that lives in freshwater ponds. Paramecia have an organelle that many cells do not have called a contractile vacuole. The function of the contractile vacuole is to collect excess water that moves into the cell. Once the contractile vacuole is full, the water is pumped out of the cell. a. Which process (diffusion, osmosis, or active transport) causes the water molecule to

move from the environment to the inside of the cell? Explain.

b. Which process causes the water molecules to move from the inside to the outside environment? Explain.

c. What would happen to the paramecium if the contractile vacuole stops functioning?

24. The 4 plant cells below were placed into different salt solutions.

One was placed into a 1% salt solution. One in a 3% salt solution. One in a 5% salt solution. One in a 10% salt solution.

a. Which cell was most likely placed into the 5% salt solution?

b. In which cell has plasmolysis occurred? Why did plasmolysis occur in this cell?

c. What salt solution is isotonic compared to the original cell?

d. Which cell has the greatest amount of turgor pressure?? In which salt solution was this cell placed?

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