1. Cell Transport
Fall 2012

2. Notes: Cell Membrane cells cytoplasm water Introduction:
A basic principle in biology is that all living things are made of ________________.
While they come in a wide variety of sizes and shapes, all cells are filled with ________________, a fluid filled inside (made up mostly of _________________) and are surrounded by a cell membrane.
cells
cytoplasm
water

3. Plasma membrane separate traffic
The cell membrane, also known as the ________________ ____________________, is the boundary that separates all living cells from their nonliving surroundings. The job of this membrane:
_______________ the cell from the outside environment
controls chemical _______________ into & out of the cell (decides what can enter & leave).
It is described as being _____________ ____________ which means it allows some substances to cross more easily than others.
Plasma membrane
separate
traffic
Selectively permeable

4. In 1972 S.J. Singer and G.L. Nicolson created the ______________ ________________ Model, which describes the structure of the cell membrane (shown below).
Fluid Mosaic

5. Lipids Proteins flexible homeostasis
The cell membrane is made up of three main types of organic compounds:
_________________ (phospholipids make up most of the cell membrane)
_________________________ (large/dark structures… act as gateways)
_________________________ (look like antennae… these are ID tags)
The cell membrane is not solid, rather it is ______________ and fluid*
By creating a barrier between the cell and its environment, it allows the cell to maintain ______________________ (internal balance).
Lipids
Proteins
carbohydrates
flexible
homeostasis

6. Lipids Phospholipids Phospholipid Water loving Water fearing
Many ______________________ bond together make up the majority of the cell membrane
The heads are water-soluble
(hydrophilic =_________ ________).
The tails are not water soluble
(hydrophobic = _________ __________)
Phospholipid
Water loving
Water fearing

7. Lipids Tail tail bilayer
The phospholipids line up ________ to ________ to form a ___________(double layer)
The hydrophobic tails are protected from the water on the inside and outside of the cell.
bilayer

8. Lipids
cholesterol
__________________ - is a lipid that helps hold the cell membrane together.

9. Proteins traffic through
Primary Function: To control chemical _______________ in & out of the cell.
traffic
Integral proteins
pass _____________ the lipid bilayer.
They allow large and/or charged molecules get into or out of the cell.
through

10. Proteins Chemical messages
Proteins are also used to receive ___________ ___________ from outside the cell.
Chemical messages
Hormones have a specific shape and travel through the blood until they find their ‘target cell’.

11. Proteins surface Peripheral Integral
Peripheral proteins located on the ___________ of the cell membrane.
surface
Peripheral
Integral

12. Carbohydrates Recognize ID TAGS Blood Type
These “antenna’ are used by the cells to help __________________ one another.
Nicknamed the cell’s ____ _______; These are unique for each person; Determine things like your _______________
Recognize
ID TAGS
Blood Type

13. Carbohydrates phospholipids proteins
Can attach to the ____________________ or the ____________ on the outer surface of a cell.
phospholipids
proteins

14. Matching B D A F G
C/D C D B

15. Cell Membrane Diagram & Q’s Cell Membrane Review page 3

18. Notes: Passive Transport pages 4-5
Fall 2012

19. Differences in Concentration
Concentration of a solution is determined by the amount of _________________ (dissolved material) you have in the amount of _____________________ (liquid its dissolved in).
solute
solvent

20. Differences in Concentration

21. Differences in Concentration
The glass on the left does not have an equal concentration throughout. The bottom of the glass is more concentrated than the top (which is dilute).
If left alone, the molecules will spread out in the glass until the concentration is equal throughout the glass (like the glass on the right).
Dilute
equal
Concentrated

22. Important Terms to Know
hypertonic
________________– a solution with a higher concentration than another solution.
________________– a solution with a lower concentration than another solution.
_____________– a solution that has an equal concentration to another.
hypotonic
isotonic

23. Passive Transport – the movement of material across a cell membrane without the use of energy.
Three types of passive transport include:
Diffusion
Osmosis
Facilitated diffusion

24. = Dots moving Diffusion
_____________- The process in which molecules of a substance move from areas of higher concentration to an area of lower concentration.
_______________is reached when the concentration is equal throughout.
Diffusion
Equilibrium

25. How does diffusion affect a cell?
Cell membranes are described as being ____________________________ since they allow some substances to pass through, but not others.
The oval represents a ________
The dotted line is the _______ ______________
Dots in the diagram are ___________(dissolved material)
Selectively permeable
cell
Cell membrane
solute

26. How does diffusion affect a cell?
In this picture, the solution _______ the cell has a higher solute concentration than the solution _________ of it.
Therefore we say the inside is ________________ to the outside of the cell or the outside is ______________ to the inside of the cell.
inside
outside
hypertonic
Before diffusion
hypotonic

27. How does diffusion affect a cell?
When the solute is small enough to pass across the cell membrane:
It will move from a high concentration to a low concentration.
Draw an arrow on the “before” diagram to show if the solute would move in or out of the cell.
Always label your arrows, so that you know what is moving across the cell membrane.
Before diffusion
Goal of diffusion
Solute (dots)

28. Selectively Permeable
Membrane

29. Facilitated Diffusion
To help
Facilitate = _______________
Facilitated Diffusion - molecules are moved across a cell membrane from an area of higher concentration to lower concentration with the help of a ____________________
Protein channel
Proteins are usually needed to move solute across the cell membrane when the solute is too _______________or _______________and can’t pass between the phospholipids.
large
charged

30. Facilitated Diffusion
The carrier protein or channel simply opens up a larger hole in the cell membrane and allows the solute to flow from one side of the cell membrane to the other (does not require __________).
energy
Before facilitated diffusion
Goal of facilitated diffusion
Solute (dots)

35. Notes: Osmosis Page 6
Fall 2012

36. Notes: Passive movement across the cell membrane (continued: Part 2)
Osmosis - The diffusion (movement) of ___________ molecules across a selectively permeable membrane.
Since it does not require energy, it is a form of PASSIVE TRANSPORT.
The goal of the water molecules is to get the substance on either side of the membrane to be at _______________ (same concentration on both sides).
water
Equilibrium

38. Draw an arrow on the diagram to show the movement of the water.
Osmosis
Below we see a concentration ____________ (difference) between the inside and the outside of the cell
The dots are solute (sugar)
The _________________is represented by the space around the dots.
Since water is a ________________ molecule, it is able to move across the cell membrane very quickly.
Water moves from an area with more water (lower solute concentration) into an area that has less water (a higher solute concentration) to dilute it.
gradient
water
Very small
Draw an arrow on the diagram to show the movement of the water.
Always label your arrows, so that you know what is moving across the cell membrane.
Water

39. Concentration Gradient
How do cells respond to being placed into solutions of different concentrations:
___________ – the bursting of an animal cell when placed in a hypotonic solution.
cytolysis

40. Concentration Gradient
How do cells respond to being placed into solutions of different concentrations:
___________________ – the force that pushes out on a plant’s cell wall when it is put into a hypotonic solution… makes cells rigid.
Turgor pressure

41. Concentration Gradient
How do cells respond to being placed into solutions of different concentrations:
______________ – the shrinking of a plant cell placed in a hypertonic solution.
animation
plasmolysis

42. Animal Cell (Red Blood Cells)
Which solution is best for an animal cell?

43. Plant Cell
Which solution is best for a plant cell?

44. H2O makes things grow Salt Shrinks
Make sure you remember the statements:
H2O makes things grow
Salt Shrinks

45. Practice Problems – page 7: The Affects of Osmosis
Osmosis is the movement of _______ across the cell membrane.
The goal is to make the concentration on the inside and outside of the cell the same.
WATER

46. Practice Problems: Osmosis – the movement of WATER (White space)
2. The cells below have just been placed into 3 different solutions. Complete each column by using the picture at the top.
Cell #1
Cell #2
Cell #3
Determine how osmosis would affect each cell shown here.
What kind of solution is each cell in? (ISOTONIC, HYPOTONIC or HYPERTONIC)
If osmosis was to occur, which direction would water move? (IN, OUT or IN & OUT)
How will the cell change? Will it SHRINK, GROW or STAY THE SAME SIZE.
Hypertonic
hypotonic
isotonic
Out in
In & out
Stay the same
shrink
grow

47. Practice Problems: Osmosis – the movement of WATER (White space)
Cell 1 Cell 2 Cell 3 3. Since an animal cell lacks a cell wall, it is important that it be surrounded by a/an (hypertonic; hypotonic; isotonic) solution, so that it does not shrink & shrivel up or swell & rupture due to the effects of osmosis. 4. If red blood cell is surrounded by a hypotonic solution, then the cell would most likely (shrink, swell or stay the same size).

48. Practice Problems: Osmosis – the movement of WATER (White space)
Cell 1 Cell 2 Cell 3 4. When plant cells are full of water, the pressure within the cell pushes out onto the cell wall, thus allowing the cell to become more rigid (has turgor pressure). Since this is a good thing for them, plant cells should be surrounded by a/an (hypertonic; hypotonic; isotonic) solution.

49. Practice Problems: Osmosis – the movement of WATER (White space)
Cell 1 Cell 2 Cell 3 6. If a plant is watered with saltwater (a hypertonic solution), then the cells would most likely (shrink, swell or stay the same size). 7. The passive movement of large molecules across the cell membrane with the help of a protein is called (diffusion, osmosis, facilitated diffusion).

50. YES
It got smaller
Question #2: What type of solution is found outside the red blood cell?
hypertonic

51. No
It stayed the same size
Question #2: What type of solution is found outside the red blood cell?
isotonic

52. yes
It got bigger
Question #2: What type of solution is found outside the red blood cell?
hypotonic

53. Passive Transport Worksheets page 8

54. Diffusion O2 To reach equilibrium Dots are O2
1. What molecules are moving?
3. Why are the arrows pointing in that direction? O2
2. Draw the arrows on the diagram above to show the direction of movement in this example.
To reach equilibrium
To have concentration be equal on the inside & outside of the cell

55. Osmosis H2O To reach equilibrium Dots are starch molecules
4. What molecules are moving?
6. Why are the arrows pointing in that direction?
H2O
5. Draw the arrows on the diagram above to show the direction of movement in this example.
To reach equilibrium
To have concentration be equal on the inside & outside of the cell

56. Facilitated Diffusion
Dots are calcium ions
7. What molecules are moving?
Calcium ions
8. Draw the arrows on the diagram above to show the direction of movement in this example.

57. Osmosis H2O Dots are sucrose molecules 9. What molecules are moving?
10. Draw the arrows on the diagram above to show the direction of movement in this example.

58. Facilitated Diffusion
Dots are sodium ions (Na+)
11. What molecules are moving?
Sodium ions
12. Draw the arrows on the diagram above to show the direction of movement in this example.

59. Diffusion O2 Dots are O2 13. What molecules are moving?
14. Draw the arrows on the diagram above to show the direction of movement in this example.

60. Notes: Active Transport page 9

61. Active Transport requires ____________to get materials across a cell membrane against a concentration difference (or gradient).
Substances are often forced to move from an area of __________concentration into an area of _________concentration (into a place that is already crowded).
energy
lower
higher

62. There are several types of Active Transport:
Protein Pumps
Endocytosis
Exocytosis

63. __________ – a special type of __________ __________ that is used to push molecules from an area of low concentration into an area of high concentration.
Ex: Sodium (Na+) and Potassium (K+) pumps.
PUMPS
Carrier protein

65. ENdocytosis Phagocytosis Pinocytosis
_________________– taking material into the cell, usually by forming pockets (called vesicles) around the material (the cell membrane folds around something outside of the cell).
____________________ – intake of large particles or cells (solid material) through the cell membrane w/in a vesicle.
_________________ – using a vesicle or pocket to take in liquid or dissolved substances (solutes).
Phagocytosis
Pinocytosis

66. Exocytosis
________________ – A vesicle from inside the cell fuses with the cell membrane, releasing their contents into the external environment.

67. The _______ ______________ prepares proteins to leave the cell by putting them in a vesicle.
Golgi Apparatus

69. Na+ The process taking place is Active Transport by protein pump.
The dots represent Na+ molecules
Na+
What molecules are moving in this example? __________
Draw the arrows on the diagram above to show the direction of movement in this example.
2. Explain why the arrows are pointing in that direction?
The goal of active transport is to increase the concentration gradient (to make unequal)

70. Practice with Active Transport page 10

71. 1. If a pump is moving material across the cell membrane, the pump requires ____________ to work because it is trying to push molecules AGAINST / WITH (circle one) the concentration gradient. 2. Unlike passive transport, a pump is trying to make the concentration of the inside and the outside of the cell EQUAL / UNEQUAL (circle one).
energy

72. 3. If active transport (a pump) is moving calcium in the above picture, which way is the calcium being pushed? INTO / OUT OF (circle one) the cell. Draw the arrows on the diagram above to show the direction of movement. 4. Explain why you think the arrow should be point in that direction? _______________________________________ ________________________________________________
In active transport, the molecules are pushed against the gradient to make the concentration unequal.

73. 6. Explain why the arrows are pointing in that direction? bacteria
The diagram to the left depicts phagocytosis by a white blood cell.
The large dot represents bacteria; the space represents water
5. What molecules are moving in this example?
Draw the arrows on the diagram above to show the direction of movement in this example.
6. Explain why the arrows are pointing in that direction?
bacteria
Phago = cell eating… taking solids IN.

74. The process taking place is pinocytosis.
The dots represent dissolved solute; the space represents water
7. What is moving?
Draw the arrows on the diagram above to show the direction of movement in this example.
Why?
Dissolved solute (or water)
Pino = cell drinking (taking liquid IN)

75. The process taking place is exocytosis .
The dots (particles) represent proteins; the space represents water
8. What is moving?
Draw the arrows on the diagram above to show the direction of movement in this example.
Why?
proteins
EXO = out… pockets pushed out of the cell.

76. A PUMP is moving material in this example.
The dots represent starch molecules; the space represents water
9. What is moving?
Draw the arrows on the diagram above to show the direction of movement in this example.
Why?
starch
Pumps push material against gradient (to make the inside & outside unequal).

77. Cell Transport Test Review pages 11 & 12