Bio Chapter 7.3 Notes. Cellular Movement

Transcription

1 Bio Chapter 7.3 Notes Cellular Movement

2 I.Background Information A. Solution- a mixture in which the solute (molecules being dissolved) never settle out in the solvent (water). B. In a 25% Koolaid solution, how much water is there?

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5 C. Every living cell contains a liquid interior (cytoplasm) and is surrounded by a liquid (fluid that baths your cells).

6 The concentration of a solution is defined as the 1. volume of solute in a given mass of solution. 2. mass of solute in a given volume of solution. 3. mass of solution in a given volume of solute. 4. volume of solution in a given mass of solute. Answer Now volume of solute in a gi... 0% 0% 0% 0% mass of solute in a given... mass of solution in a giv.. volume of solution in a... 20

7 II. Homeostasis A. Process where the cell/organism tries to maintain a constant internal environment. 1.E.g. Body temperature, blood sugar, and body fluids.

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10 The plasma membrane (cell membrane) is. 1. a single-layered membrane that surrounds the nucleus of the cell 2. a double layer of protein enclosing the plasma 3. the phospholipid bilayer surrounding the cell 4. a membrane composed of tiny shelves or cristae Answer Now 25% 25% 25% 25% 22

11 B. Cells maintain homeostasis by controlling what enters and leaves the cell via the cell (plasma) membrane.

12 1. It is selectively (semi-) permeable it allows some molecules to move in/out of the cell

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14 Active Art Diffusion

15 Which of the following is a function of the 1. breaks down lipids, carbohydrates, and cell membrane? proteins from foods 2. stores water, salt, proteins, and carbohydrates 3. keeps the cell wall in place 4. regulates which materials enter and leave the cell Answer Now breaks down lipids, carb... 0% 0% 0% 0% stores water, salt, protein.. keeps the cell wall in place regulates which material... 20

16 The model describing the structure of the cell membrane is known as. 1. the sandwich model. 2. the fabric model. 3. the mosaic tile model. 4. the fluid mosaic model. 0% 0% 0% 0% the sandwich model. the fabric model. the mosaic tile model. Answer Now 18 the fluid mosaic model.

17 III. Cell Membrane A. Structure: Fluid Mosaic Model parts are not in fixed positions, they are free to float along the bilayer (sea of fat)

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19 Label: Glycoprotein, Glycolipid, Integral protein, Peripheral protein AND Cholesterol

20 1. Double bilayer of lipids with imbedded, dispersed proteins

21 2. Bilayer consists of phospholipids, cholesterol, and glycolipids a. Glycolipids are lipids with bound carbohydrate, found in outer membrane

22 Phospholipids. 1. are exclusively hydrophilic molecules 2. contain polar tails and nonpolar head groups 3. are both hydrophilic and hydrophobic in nature 4. form the lipid bilayer, with tails directed to the outside 25% 25% 25% 25% Answer Now 20

23 b. Phospholipids have two hydrophobic (water hating) tails and a hydrophilic (water loving) head i. The center section of the lipid bilayer is hydrophobic, either side of the bilayer (in/out of the cell) is hydrophilic.

24 ii. The regions of the protein embedded in the bilayer are hydrophobic; the regions of protein exposed to the internal/external environment of the cell are hydrophilic.

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26 Polar region of phospholipid A. A B. B C. C D. D E. E Answer Now A 0% 0% 0% 0% 0% B C D 15 E

27 a. Polar molecules have a difference in charges; therefore attract ions like Na +, Ca +2, and K + Dissolving Salt in Water-Physical Animation: g_salt.swf

28 Simple diffusion may involve the movement of through the plasma membrane down a concentration gradient. 1. small polar molecules 2. small nonpolar molecules 3. large polar molecules 4. large nonpolar molecules 0% 0% 0% 0% Answer Now all polar molecules onpolar molecules ge polar molecules onpolar molecules 20

29 3. Draw a single phospholipid (label: head, tails, hydrophobic and hydrophilic end); Draw the phospholipd bilayer membrane.

30 Which of the following is a principle of the fluid mosaic model of cell membrane structure? 1. Phospholipids form a bilayer that is largely impermeable to water-soluble molecules. 2. Phospholipids consist of a polar head and a nonpolar tail made of three fatty acid chains. 3. The lipid bilayer is a solid at body temperature, thus protecting the cell. 4. All proteins associated with the cell membrane are contained in a fluid layer on the outside of the cell. Answer Now 25% 25% 25% 25% 30

31 Which of the following would not be a constituent of a plasma membrane? 1. glycolipids 2. messenger RNA 3. glycoproteins 4. phospholipids 0% 0% 0% 0% glycolipids messenger RNA glycoproteins phospholipids Answer Now 18

32 4. Functions of Membrane Proteins molecules floating in sea of fat allow: a. Transport i. Carrier Proteins bind to a substance and transport it across the membrane down the concentration gradient (High to low)

33 ii. Channel Proteins form pores or passageways for molecules to move through the membrane down the concentration gradient

34 b. Enzymatic activity

35 c. Receptors for signal transduction

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37 i. Contact signaling important in normal development and immunity

38 ii. Electrical signaling voltage-regulated ion gates in nerve and muscle tissue

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40 iii. Chemical signaling neurotransmitters bind to chemically gated channel-linked receptors in nerve and muscle tissue

41 d. Intercellular adhesion (CAM s)

42 i. Anchor cells to the extracellular matrix

43 ii. Assist in movement of cells past one another

44 iii. Rally protective white blood cells to injured or infected areas

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46 e. Cell-cell recognition identify the cell

47 Identification "tags" for the cell A. A B. B C. C D. D E. E Answer Now A 0% 0% 0% 0% 0% B C D 15 E

48 f. Attachment to cytoskeleton and extracellular matrix

49 Which of the following is a function of a plasma membrane protein? 1. circulating antibody 2. molecular transport through the membrane 3. forms a lipid bilayer 0% 0% 0% 0% 4. oxygen transport circulating antibody molecular transport th... forms a lipid bilayer oxygen transport Answer Now 20

50 IV. Transport across the membrane A. Label Diagram

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53 B. Phospholipid bilayer prevents large molecules (like sugars and amino acids) from passing through the membrane.

54 C. Water molecules are small enough to diffuse across the lipid bilayer.

55 The cell membrane contains channels and pumps that help move materials from one side to the other. What are these channels and pumps made of? 1. carbohydrates 2. lipids 3. bilipids 4. proteins 0% 0% 0% 0% Answer Now carbohydrates lipids bilipids proteins 18

56 Cell Wall vs. Cell Membrane Composition

57 Unlike a cell wall, a cell membrane 1. is composed of a lipid bilayer. 2. provides rigid support for the surrounding cell. 3. allows most small molecules and ions to pass through easily. 4. is found only in plants, fungi, algae, and many prokaryotes. Answer Now is composed of a lipid bil... 0% 0% 0% 0% provides rigid support fo... allows most small molecu... is found only in plants, f... 20

58 You will NOT find a cell wall in which of these kinds of organisms? 1. plants 2. animals 3. fungi 4. all of the above 0% 0% 0% 0% Answer Now plants animals fungi all of the above 15

59 V. Passive Processes (No energy required) A. Diffusion- Random mixing of particles in a solution as a result of the particle s kinetic energy

60 Diffusion is the movement of molecules from 1. an area of low concentration to an area of high concentration. 2. an area of high concentration to an area of low concentration. 3. an area of equilibrium to an area of high concentration. 4. all of the above Answer Now an area of low concentra... 0% 0% 0% 0% an area of high concentr... an area of equilibrium to... all of the above 25

61 1. More molecules move randomly from an area of high concentration to an area of low concentration (down their concentration gradients)

62 2. It s the solute that moves in and out of the cell if it can pass through the plasma membrane

63 3. The following conditions affect the rate of diffusion (how fast the solute moves across the membrane): a. The greater the difference in concentration between the 2 sides of the membrane, the faster the rate of diffusion

64 If a substance is more highly concentrated outside the cell than inside the cell and the substance can move through the cell membrane, the substance will 1. move by diffusion from inside the cell to outside. 2. remain in high concentration outside the cell. 3. move by diffusion from outside to inside the cell. 4. cause water to enter the cell by osmosis. Answer Now move by diffusion from i... 0% 0% 0% 0% remain in high concentra... move by diffusion from o... cause water to enter the... 25

65 b. The higher the temperature, the faster the rate of diffusion

66 c. the larger the size of the diffusing substance, the slower the rate of diffusion

67 d. an increase in surface area, increases the rate of diffusion

68 e. Greater diffusion distance, slower rate of diffusion

69 Which of the following statements is correct regarding diffusion? 1. The rate of diffusion is independent of 25% temperature. 2. The greater the concentration gradient, 25% the faster the rate of diffusion. 3. Molecular weight of a substance does not affect the rate of diffusion. 25% 4. The lower the temperature, the faster the 25% diffusion rate Answer Now 25

70 4. When the molecules are equal, equilibrium has been reached

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72 5. Indicate the direction of solute movement by drawing an arrow in the direction of flow for each diagram or

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74 When the concentration of molecules on both sides of a membrane is the same, the molecules will 1. move across the membrane to the outside of the cell. 2. stop moving across the membrane. 3. move across the membrane in both directions. 0% 0% 0% 0% 4. move across the membrane to the inside of the cell. Answer Now move across the membra.. stop moving across the... move across the membr... move across the membra.. 20

75 What do you already know? The diffusion of water across a selectively permeable membrane is called 1. osmotic pressure. 2. osmosis. 3. facilitated diffusion. 4. active transport. 0% 0% 0% 0% Answer Now osmotic pressure. osmosis. facilitated diffusion. active transport. 18

76 B. Osmosis - Net movement (diffusion) of water through a semi-permeable membrane from an area of high water concentration to an area of low water concentration

77 1. Water is most concentrated where there is the least solute concentration. 2. Water moves to concentrated solutions (high solute concentrations).

78 3. Only occurs if membrane is permeable to water but not to certain solutes

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80 4. Indicate the direction of water movement by drawing an arrow in the direction of flow

81 5. Tonicity how a solution affects cell volume

82 a. Isotonic solutions with the same solute concentration as that of the cytosol (the concentration of solutes if equal inside and outside the cell)

83 b. Hypertonic solutions having greater solute concentration than that of the cytosol (the concentration of solutes is greater outside the cell than it is inside)

84 i. In plant cells, the central vacuole loses water and the cells shrink, causing wilting. ii. In animal cells, the cells also shrink.

85 c. Hypotonic solutions having lesser solute concentration than that of the cytosol (the concentration of solutes is greater inside the cell than it is outside)

86 ii. In plants the central vacuole fills and the plants are rigid (but the cell wall keeps it from bursting)

87 iii. In animals the cell could lyse (burst) unless certain organelles pump water out quickly!

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90 6. Osmotic Pressure - Pressure created by osmosis (pg. 186) a. Cells are filled with sugars, salts, proteins, and other molecules which cause a pressure to build up on the hypertonic side of the membrane (or inside the cell).

91 b. If a cell is placed in fresh water, water will rush into the cell causing is to swell and burst (Lyse).

92 c. If this is true, why aren t your cells expanding and exploding right now?????? i. Our cells are bathed by blood, which is isotonic with the fluid in our cells. This means that the solute concentration inside the cell is the same as that in the blood.

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95 If the concentration of solutes in a cell is less than the concentration of solutes in the surrounding fluid, then the extracellular fluid is said to be: 1. hypertonic. 2. hypotonic. 3. isotonic. 4. stable. 0% 0% 0% 0% Answer Now hypertonic. hypotonic. isotonic. 20 stable.

96 If cells are placed in a hypertonic solution containing a solute to which the membrane is impermeable, what could happen? 1. The cells will swell and ultimately burst. 25% 2. The cells will lose water and shrink. 25% 3. The cells will shrink at first, but will later reach equilibrium with the surrounding 25% solution and return to their original condition. 4. The cells will show no change due to diffusion of both solute and solvent. Answer Now 25%

97 Resources\Resources 7-3\ActiveArt\osmosis_index.html

98 An animal cell that is surrounded by fresh water will burst because the osmotic pressure causes 1. water to move into the cell. 2. water to move out of the cell. 3. solutes to move into the cell. 4. solutes to move out of the cell. 0% 0% 0% 0% Answer Now water to move into the cell. water to move out of the... solutes to move into the... solutes to move out of t.. 20

99 Which of the following statements about the red blood cells in Figure 7.02 beaker A is true? 1. There has been no net water movement. 2. There has been a net flow of water out of the cell. 3. There has been a net flow of water into the cell. 4. Pinocytosis has occurred 0% 0% 0% 0% Answer Now There has been no net wat.. There has been a net flow o... There has been a net flow o... Pinocytosis has occurred 20

100 Which of the following statements about the red blood cells in Figure 7.02 beaker B is true? 1. These red blood cells have shrunken in response to a hypertonic external solution. 2. These red blood cells have shrunken in response to a hypotonic external solution. 0% 0% Answer Now These red blood cells hav... These red blood cells ha.. 20

101 C. Facilitated Diffusion Transport Proteins with in the membrane make it easier for certain molecules to enter the cell

102 Facilitated Diffusion Glucose molecules Protein channel

103 1. Solutes move down their concentration gradients

104 2. Carrier proteins allow large molecules (like sugars and amino acids) to cross the membrane

105 3. Channel proteins provide a safe crossing for ions across the cell membrane a. Ion channels can contain gates that can open or close depending on internal/external conditions of the cell i. This allows the cell to control when ions can enter/exit the cell.

106 The process by which molecules diffuse across a membrane through protein channels is called 1. active transport. 2. endocytosis. 3. facilitated diffusion. 4. osmosis. 0% 0% 0% 0% Answer Now active transport. endocytosis. facilitated diffusion. osmosis. 20

107 VI. Active Processes - (energy required ATP) A. Active Transport - molecules moved across membrane from low concentrations to high concentrations ( up their concentration gradients) with the help of membrane proteins

108 Active Transport Molecule to be carried

109 1. Types of Active Transport a. Primary active transport hydrolysis of ATP, phosphorylates the transport protein causing conformational change (change of shape)

110 b. Secondary active transport use of an exchange pump (such as the Na + -K + pump) indirectly to drive the transport of other solutes

111 Sodium-Potassium Exchange Pump r6/animations.html

112 i. The sodium potassium pump (Na + -K + ) moves (1) 3 sodium ions out of the cell (2) 2 potassium ions into the cell

113 (3) Since both ions are positive (+) the net charge on the inside of the plasma membrane becomes negative (-)

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115 (4) The difference in charge is important in the conduction of electrical impulses (neurons)

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117 The sodium-potassium pump 1. pumps Na+ and K+ out of the cell. 2. pumps Na+ and K+ into the cell. 3. pumps Na+ into and K+ out of the cell. 4. pumps Na+ out of and K+ into the cell. pumps Na+ and K+ out o... 0% 0% 0% 0% Answer Now 20 pumps Na+ and K+ into t.. pumps Na+ into and K+... pumps Na+ out of and K+...

118 When movement of Na + ions down their concentration gradient drives the transport of other substances across the cell membrane, it is called. 1. primary active transport 2. secondary active transport 3. vesicular transport 4. pumping primary active transport 0% 0% 0% 0% secondary active transport vesicular transport pumping Answer Now 20

119 Osmosis does not involve 1. a selectively permeable membrane 2. a difference in solvent concentration 3. diffusion 4. active transport a selectively permeable... 0% 0% 0% 0% a difference in solvent c... diffusion active transport Answer Now 20

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121 Resources\Resources 7-3\ActiveArt\active_transoirt_index.html

122 Passive membrane transport processes include. 1. movement of water from an area of low concentration to an area of high concentration 2. consumption of ATP 3. movement of a substance down its concentration gradient 4. the use of transport proteins when moving substances from areas of low to high concentration Answer Now 25% 25% 25% 25% 25

123 2. Types of Vesicular Transport-transport of large particles and macromolecules across plasma membranes a. Endocytosis - surrounding a substance with some of the plasma membrane and then, bringing it into the cell, within a vesicle (vacuole). It s a vacuole if it just stores the substance

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125 Cells that store large quantities of chemicals to be released do so in structures called. 1. snares 2. docking sacs 3. fusion sacs 4. vesicles 0% 0% 0% 0% snares docking sacs fusion sacs vesicles Answer Now 20

126 i. Phagocytosisbringing in solids-like food and cells.

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128 ii. Pinocytosisbringing in liquids.

129 Inner Surface of Plasma Membrane Yellow arrow: Clathrin-coated pits White arrow: Clathrin-coated vesicle Small micrograph: Caveolae

130 Endocytosis of LDL tm

131 Endocytosis and Exocytosis ter6/animations.html

132 b. Exocytosis - opposite of endocytosis i. Expels contents of vesicles out of the cell

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134 ii. This is a way to rid the cell of wastes. iii. Restores the membrane, so the cell doesn t shrink.

135 The process illustrated in Figure 7.01 is called: 1. facilitated diffusion. 2. pinocytosis. 3. lysis. 4. exocytosis. 0% 0% 0% 0% ilitated diffusion. pinocytosis. lysis. exocytosis. Answer Now 20

136 A human white blood cell engulfs a bacterial cell by: 1. carrier-mediated facilitated diffusion. 2. exocytosis. 3. phagocytosis. 4. pinocytosis. Answer Now carrier-mediated facilita... 0% 0% 0% 0% exocytosis. phagocytosis. pinocytosis. 20

137 c. Transcytosis moving substances into, across, and then out of a cell

138 d. Vesicular trafficking moving substances from one area in the cell to another

139 Which of the following is NOT an example of simple diffusion? 1. gas exchange in our lungs 2. a dissolving sugar cube 3. popcorn odor permeating the room 4. a white blood cell engulfing a bacterium xchange in our lungs 0% 0% 0% 0% Answer Now 20 issolving sugar cube n odor permeatin... blood cell engulfi..

140 In areas of the body exposed to the external environment, such as the lungs, you would expect which type of vesicular transport to 1. exocytosis 2. pinocytosis 3. phagocytosis be most prevalent? 4. receptor-mediated endocytosis exocytosis 0% 0% 0% 0% pinocytosis phagocytosis Answer Now 20 receptor-mediated end...

141 e. Draw and label Endocytosis, Transcytosis and Exocytosis

142 A bottle of perfume is opened on the opposite side of the room and within minutes you begin to smell the perfume. This phenomenon is a classic example of: 1. facilitated diffusion. 2. osmosis. 3. active transport. 4. simple diffusion. 0% 0% 0% 0% Answer Now facilitated diffusion. osmosis. active transport. simple diffusion. 20

143 The movement of materials in a cell against a concentration difference (from low to high concentration) is called 1. facilitated diffusion. 2. active transport. 3. osmosis. 4. diffusion. 0% 0% 0% 0% Answer Now facilitated diffusion. active transport. osmosis. diffusion. 20