2.3 Transport Across Cell Membranes Flashcards

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1
Q

What model do all membranes have

A

Fluid-mosaic

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2
Q

What are the major components to the cell membrane

A
  • Phospholipid Bilayer
  • Channel Protein
  • Carrier Protein
  • Glycoprotein
  • Glycolipid
  • Cholesterol
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3
Q

Name the component of the cell membrane

A

Phospholipid Bilayer

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4
Q

Name the component of the cell membrane

A

Channel Protein

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5
Q

Name the component of the cell membrane

A

Glycoprotein

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6
Q

Name the component of the cell membrane

A

Carrier Protein

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7
Q

Name the component of the cell membrane

A

Glycolipid

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8
Q

Name the component of the cell membrane

A

Cholesterol

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9
Q

Describe the arrangement of phospholipid molecules in the phospholipid bilayer

A
  • Two layers of phospholipids
    Hydrophilic heads face outside
  • Hydrophobic tails face inside
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10
Q

Describe and explain the advantages of the phospholipid bilayer in the cell membrane

A
  • Selectively-permeable barrier
  • Only non-polar molecules are able to pass through via simple diffusion
  • Bilayer is fluid
  • Can bend to take up different shapes, forming vesicles
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11
Q

Describe and explain the advantages of channel proteins in the cell membrane

A
  • Protein through bilayers
  • Allows water soluble substances through via faccilitated diffusion
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12
Q

Describe and explain the advantages of carrier proteins in the cell membrane

A
  • Protein through bilayer
  • Allows substances to move through via faccilitated diffusion and active transport
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13
Q

Describe and explain the advantages of glycoproteins in the cell membrane

A
  • Protein with short carbohydrate chain
  • Cell recognition and signalling
  • Cell attachment
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14
Q

Describe and explain the advantages of glycolipids in the cell membrane

A
  • Phospholipid with short carbohydrate chain
  • Cell recognition and signalling
  • Cell attachment
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15
Q

Describe and explain the advantages of cholesterol in the cell membrane

A

Regulates membrane fluidity

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16
Q

Simple diffusion: Movement of molecules

A
  • Along concentration gradient
  • From higher concentration to lower concentration
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17
Q

Simple diffusion: Active or passive

A
  • Passive
  • No ATP hydrolysed
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18
Q

Simple diffusion: Movement through what

A

Diffuse through phospholipid bilayer

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19
Q

Simple diffusion: Type of molecule

A

Non-polar

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20
Q

Faccilitated diffusion: Movement of molecules

A
  • Along concentration gradient
  • From higher concentration to lower concentration
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21
Q

Faccilitated diffusion: Active or passive

A
  • Passive
  • No ATP hydrolysed
22
Q

Faccilitated diffusion: Movement through what

A

Channel and carrier proteins

23
Q

Faccilitated diffusion: Type of molecule

A

Polar / Charged

24
Q

Osmosis: Movement of molecules

A
  • Movement of water along a water potential gradient
  • From an area of high water potential
  • To an area of low water potential
25
Q

Osmosis: Movement of molecules regarding solute concentration

A

Low to high solute concentration

26
Q

Osmosis: Passive or active

A
  • Passive
  • No ATP hydrolysed
27
Q

Osmosis: Movement through what

A

Water channel proteins (aquaporins)

28
Q

Water IN by osmosis : Cell apperance

A

Turgid

29
Q

Water IN by osmosis : Cytoplasm

A

Hasn’t shrunk from cell wall

30
Q

Water IN by osmosis : Cell in what solution

A

Hypotonic

31
Q

Water IN by osmosis : Water potential of cell and solution

A

Solution has higher water potential than cell

32
Q

Water IN by osmosis : Net movement of water

A

Into the cell by osmosis

33
Q

Water OUT by osmosis : Cell appearance

A

Plasmolysed

34
Q

Water OUT by osmosis : Cytoplasm

A

Shrunk from cell wall

35
Q

Water OUT by osmosis : Cell in what solution

A

Hypertonic

36
Q

Water OUT by osmosis : Water potential of cell and solution

A

Solution has a lower water potential than the cell

37
Q

Water OUT by osmosis : Net movement of water

A

Out of the cell, by osmosis

38
Q

Water potential of pure water

A

0kPa

39
Q

Water potential of a solution more concentrated than pure water

A

Less than 0kPa

40
Q

Relationship between water potential and solute concentration

A

More concentrated solute = lower water potential

41
Q

Active Transport: Movement of molecules

A
  • Against concentration gradient
  • From lower concentration to higher concentration
42
Q

Active Transport: Active or passive

A
  • Active
  • Requires ATP hydrolysis
43
Q

Active Transport: Movement through what (+description)

A
  • Carrier protein
  • Protein changes shape, as substrate binds
44
Q

What occurs when a substrate binds to a carrier protein

A

Protein changes shape

45
Q

Describe exocytosis

A

Fusion of a vesicle with the cell-surface membrane

46
Q

Describe endocytosis

A

Engulfment of molecules by cell-surface membrane to form vesicles

47
Q

State the ways in which cells adapt to increase the rate of transport across a membrane

A
  • Increased number of channel and carrier proteins
  • Folded membrane
  • Increased number of mitochondria
48
Q

Describe how increasing the number of channel/carrier proteins increases the rate of transport across a membrane

A

More faccilitated diffusion / active transport

49
Q

Describe how a folded membrane increases the rate of transport across a membrane

A

Increases surface area

50
Q

Describe how an increased number of mitochondria increases the rate of transport across a membrane

A

Supply more ATP for active transport