5.5-5.11 Quiz/Vocab Flashcards

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1
Q

what do membrane proteins do?

A

specialize

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2
Q

in what ways to membrane proteins specialize?

A

anchor cells to substrates
transport molecules
catalyze enzymatic reactions
receive information
identification tags

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3
Q

what does it mean for biological membranes to be selectively permeable?

A

for membranes to allow some but not all substances to pass

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4
Q

what is the membrane permeable to?

A

small non polar molecules and some small polar molecules; water is small enough to pass through gaps slowly

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5
Q

what is the bilayer impermeable to?

A

to charged ions and most large polar molecules

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6
Q

are gases such as N2, O2, and CO2 permeable?

A

yes

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7
Q

are hydrophobic non polar molecules permeable?

A

yes

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8
Q

are small polar molecules such as H2O, glycerol, and urea permeable?

A

yes

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9
Q

are large polar molecules such as glucose and uncharged mono & disaccharides permeable?

A

NO

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10
Q

are ions and electorally charged molecules permeable?

A

NO

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11
Q

How do impermeable substances cross the membrane?

A

via transport proteins (carrier and channel)

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12
Q

what are carrier proteins?

A

proteins that change shape and transfer molecules

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13
Q

What does carrier mediated transport transfer?

A

solutes

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14
Q

what are the two forms of carrier-mediated transport?

A

active and passive transport

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15
Q

what do transfer proteins do?

A

form pores in the membranes that allow passive transport (diffusion) of water and ions

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16
Q

what is diffusion?

A

the movement of ions and small molecules down a concentration gradient and through the membrane (simples and facilitated)

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17
Q

what is concentration gradient?

A

when particles in a liquid or gas are unevenly distributed

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18
Q

how does diffusion move across concentrations?

A

from an area of high concentration to an area of low concentration

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19
Q

what is a membrane gradient?

A

potential energy capable of doing work

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20
Q

how is the rate of diffusion determined?

A

by size, shape, and the charge of particles as well as temperature

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21
Q

what is dynamic equilibrium?

A

occurs due to diffusions where particles are uniformly distributed with no net change to the system

22
Q

what is simple diffusion?

A

small, non polar solutes moving directly through the membrane and down the concentration gradient

23
Q

what is facilitated diffusion?

A

specific proteins make the membrane permeable to specific ions or polar molecules

24
Q

what do channel proteins do?

A

form hydrophilic channels where specific ions move down their electrochemical gradients

25
Q

what is osmosis?

A

the net movement of water through a selectively permeable membrane from high concentrations of water to lower concentrations

26
Q

what is osmotic pressure?

A

exerted on the side contains the higher solute concentration to prevent the diffusion of water from the other side

27
Q

what is an isotonic solution?

A

no net movement of water molecules

28
Q

what is a hypertonic solution?

A

high concentration of solutes outside of the cell; cell’s loose water and shrink

29
Q

what is a hypotonic solution?

A

lower confute concentration out the cell; cell gains water and swells

30
Q

what is tonicity?

A

whether or not a cell is isotonic, hypotonic, or hypertonic ; relative compared to another solutions

31
Q

when cells shrinks in hypertonic solutions?

A

crenation (animals), and plasmolysis (plants)

32
Q

when cells swell in hypotonic solutions?

A

hemolysis (animals), turgor pressure (plants)

33
Q

what is active transport?

A

metabolic energy is used to pump materials from low concentration to high concentration

34
Q

what is indirect active transport?

A

a concentration gradient provides energy for the co-transport of another substance

35
Q

what energy source does a NA-K pump use?

A

ATP to pump NA+ out of the cell and K+ into the cell

36
Q

What does ATP produce?

A

a concentration gradient

37
Q

what is a cotransport system?

A

energy produced by moving solute down its concentration gradient is used to transport another solute up its concentration gradient

38
Q

what does cotransport do?

A

indirectly provide energy for active transport

39
Q

what is exocytosis?

A

vesicles export large molecules by fusing a vesicle with the plasma membrane

40
Q

how does endocytosis import material?

A

through phagocytosis, pinocytosis or receptor-mediated endocytosis

41
Q

what is phagocytosis?

A

cellular eating; folding of the plasma membrane encloses a cell or food particle, forming a vacuole which can fuse with lysosomes

42
Q

what is pinocytosis?

A

drinking; fluid with dissolved materials is drawn in by folds in the plasma membrane

43
Q

what is receptor mediated endocytosis?

A

specific molecules combine with receptor proteins in the membrane

44
Q

what do junctions do?

A

connect cells that form strong connection, preventing passage of materials, or establishing rapid communication between adjacent cells

45
Q

what types of junctions are there?

A

anchoring, tight, gap, and plasmodesmata

46
Q

what do anchoring junctions do?

A

connect cells of an epithelial sheet; cadherins are important protein component

47
Q

what are two types of anchoring junctions?

A

desmosomes, and adhering junctions

48
Q

what do tight junctions do?

A

seal off intercellular spaces between some animal cells, allowing no space to remain between the cells

49
Q

what do gap junctions do?

A

allow the transfer of small molecules and ions, communication; can open and close, connexion molecules group to for cylinders

50
Q

what does plasmodesmata do?

A

allow for movement between the cells