3: movement into and out of cells Flashcards

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1
Q

what is the role of membranes in the cell?

A
  • allows chemical reactions on the surface
  • enables cells to receive hormone messages
  • forms and controls an ionic gradient
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2
Q

what is the phospholipid bilayer?

A
  • hydrophobic and hydrophilic lipid molecule layers that float in a fluid
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3
Q

list the components of the membrane

A
  • phospholipid bilayer
  • proteins
  • cholesterol
  • glycolipids and glycoproteins
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4
Q

what is diffusion?

A

the net movement of solutes across a partially permeable membrane from a region of high concentration to a region of low concentration due to the random movement of particles

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5
Q

what kind of transport is diffusion?

A

passive transport- does not require energy

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6
Q

what are the types of diffusion?

A
  • simple diffusion
  • facilitated diffusion
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7
Q

what are the factors affecting the rate of diffusion across the membrane? [6]

A
  • steepness of the concentration gradient
  • temperature
  • surface area
  • distance
  • nature of mol/ion [size and polarity]
  • solubility of lipid/fat
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8
Q

why can’t large, polar molecules pass through the ppm?

A

the size and charge of these molecules make it too difficult for them to pass through the non-polar region without the use of proteins

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9
Q

where do charged ions pass through the ppm?

A

carriers made by protein molecules

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10
Q

what is facilitated diffusion

A
  • diffusion but through a protein channel
  • not energy dependent
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11
Q

what is the difference between carrier proteins and protein channels?

A
  • protein channels work with the conc. gradient
  • carrier proteins work against the conc. gradient
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12
Q

what is osmosis?

A

the net movement of water molecules from a region of high water potential to a region of low water potential

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13
Q

what is water potential?

A

tendency of water to move from one place to another

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14
Q

what is the water potential of pure water?

A

0

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15
Q

what happens when equilibrium is reached in osmosis?

A

there will be no net movement of water

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16
Q

describe the osmosis in an animal cell if:
- water potential of solution is high
- water potential of solution is low

A
  • cell swells and bursts
  • cell crenates
17
Q

describe the osmosis in a plant cell if:
- water potential of solution is high
- water potential of solution is low

A
  • water pont. increases inside until equilibrium is reached (cell becomes turgid)
  • plasmolysis happens and there is no wall pressure (flaccid)
18
Q

what is plasmolysis?

A

when the cell membrane and vacuole shrinks and starts to pull away from the cell wall

19
Q

what is active transport?

A

movement of solutes across the ppm using carrier proteins

20
Q

what does active transport require?

A
  • ATP to help change the shape of carrier proteins
21
Q

what is the Na K pump?

A

carrier proteins that pumps out Na ions and allows in K ions

22
Q

where is the Na K pump found?

A

found at the surface of cell membranes

23
Q

what does the Na K pump do?

A

controls the osmotic balance of cells

24
Q

what is bulk transport?

A

transportation of large molecules

25
Q

what is endocytosis?

A

active transport of solutes into a cell

26
Q

what is exocytosis?

A

active transport of solutes out of the cell

27
Q

what is phagocytosis?

A

phagocytes forming a phagocytic vacuole (ENGULFING!!!!)

28
Q

what is exocytosis?

A

transport of materials out the cell