chapter 5 structure and function plasma membranes Flashcards

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1
Q
MEMBRANE STRUCTURE 
highly \_\_\_\_\_\_\_\_\_
\_\_\_\_\_\_\_\_ are arranged in a bilayer 
globular \_\_\_\_\_\_ insert into the lipid bilayer 
fluid mosaic model-
A

organized
phospholipids
proteins
mosaic of proteins floating in/on the fluid lipid bilayer

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2
Q

4 components of cell membrane

A

phospholipid bilayer
transmembrane protein
interior protein network
cell surface markers

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3
Q

the fluid mosaic model of the plasma membrane describes the plasma membrane as a fluid combination of _______, ______, and _______.

______ attach to the lipids and proteins extend from the outward facing surface of the membrane

A

phospholipids, cholesterol, and proteins

carbohydrates

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4
Q

phospholipid structure consists of

A

glycerol (a 3-carbon polyalcohol)
2 fatty acids attached to the glycerol
a phosphate group attached to the glycerol

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5
Q

BILAYER
fatty acids are on the ______
phosphate groups are on ____ surfaces.

A

inside

both

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6
Q

the phospholipid bilayer is composed of a ______ head and two _____ tails.
the ____ consists of a phosphate-containing group attached to a _____ molecule.
the tails contain either _____ or an ______ fatty acid.
their hydrophobic tails face ______.

A

hydrophilic, hydrophobic
head, glycerol
saturated, unsaturated
inward

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7
Q

membrane proteins

A
tansporters
enzymes 
cell-surface identity markers
cell-surface receptor
cell-to- cell adhesion proteins 
attachments the the cytoskeleton
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8
Q

mom-polar regions of the protein are embedded in the ______ of the bilayer

poplar regions of the protein profited from ____ sides of the bilayer

A

interior

both

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9
Q

the transmembrane domain _____ the lipid bilayer

hydrophobic amino acids arrange into a ______

A

spans

helice

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10
Q

interfere membrane proteins may have one or more ____-____ that span the membrane, or they may have ___-____ that span the membrane

A

alpha-helices

beta-sheets

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11
Q

HIV binds to the ___ receptor, a glycoprotein in the surfaces of t-cells

A

CD4

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12
Q

PASSIVE TRANSPORT
movement of ______ through a membrane
no _____ required
molecules move in response to a ______ gradient
diffusion is…
will continue until the _____ is same in all regions.

A
molecules 
energy 
concentration 
movement of molecules from high to low concentration
same
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13
Q

major barrier to crossing a biological membrane is the hydrophobic interior that _____ polar molecules.

_______ molecules will move until the concentration is ______ on both sides

limited permeability to _____ polar molecules and ions

A

repels

nonpolar, equal

larger

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14
Q

diffusion through a permeable membrane moves a substance from an area of ____ concentration down the concentration ______.

A

high, gradient

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15
Q

______ transport moved substances down the concentration gradients. they may pass the plasma membrane with aid of…

A

facilitated, channel proteins

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16
Q

major barrier of the plasma membrane ____ ____, thst repels _____ molecules, but not _____ molecules

A

hydrophobic interior, polar, nonpolar

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17
Q

nonpolar molecules will move until the concentration is ____ on both sides.

limited permeability for _____ polar molecules, and very limited permeability for ____ polar molecules and atoms

A

equal

small, larger

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18
Q

molecules that can’t pass the membrane easily may enter through ___

A

protein so

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19
Q

channel proteins are

carrier proteins

A

hydrophilic channel (when open)

bind themselves to molecules they assist

20
Q

membrane is _____ permeable

A

selectively

21
Q

___ ______ allow passage of ions.

A

ion channels

22
Q

gated channels:

A

open or close in response to stimulus message

23
Q

CONDITIONS TO DETERMINE MOVEMENT
relative concentration on _____ side on membrane
______ differences across membrane
gated channels either ____ or _____

A

either
voltage
open or closed

24
Q

cytoplasm of the cell is an ______ solution
water is a _______
dissolved substances are ______

A

aqueous
solvent
solute

25
Q

osmosis is

A

the nest diffusion of water across a membrane toward a higher solute concentration

26
Q

hypertonic have a _____ solute concentration

hypotonic has a ____ solute concentration

A

higher

lower

27
Q

when two solutions have the same osmotic concentration, the solutions are ______

A

isotonic

28
Q

aquaporins _______ osmosis

A

facilitate

29
Q

OSMOTIC PRESSURE
_____ is needed to stop osmotic flow
cells in a hypotonic solution gain water, causing it to _____ and creating _____
if the membrane is strong enough, the cell ____ _____ osmotic pressure
if membrane is weak, cell may _____
animal cells must be in ______ environments

A
force
swell, pressure
counter balances
burst
isotonic
30
Q

some cells use ____, where water is ejected through contractile vacuoles
___ ______ involves keeping cells isotonic with their environment
marine organisms adjust internal ______ to match sea water
terrestrial animals ______ isotonic fluid
plant cells use _____ _____ to push the cell membrane against the cel wall to keep it rigid

A
execution
isosmotic regulation
concentration 
circulate 
turgor pressure
31
Q

___ is used directly or indirectly to fuel active transport
moves substances from ____ to ____ concentration
requires the use of…

A

ATP
low to high
highly selective carrier proteins

32
Q

types of carrier proteins

A

uniporters (move one molecule)
symporters (move two molecules in the same direction)
antiporters (move two molecules in opposite directions)

33
Q

the ____-_____ _____ directly uses ATP for active transport

A

sodium-potassium pump

34
Q

the sodium potassium pump moves __ Na+ out of the cell and __ K+ into the cell.
goes _____ the concentration gradient
ATP energy is used to change the ______ of the carrier protein
affinity of the carrier protein for either Na+ or K+ changes so the ____ can be carried across the membrane

A

3,2
against
confirmation
ions

35
Q

COUPLED TRANSPORT
uses ATP _______
uses energy released when a molecule moves by _______ to supply energy to active transport another molecule
_______ is used
Na+ support captures the energy from Na+ diffusion to move ______ against a concentration gradient

A

indirectly
diffusion
symporter
glucose

36
Q
BULK TRANSPORT
1. endocytosis
movement of \_\_\_\_\_ in the cell
phagocytosis cells take in \_\_\_\_\_\_\_ \_\_\_\_
pinocytosis cells take in only \_\_\_\_\_\_
receptor-meditated endocytosis is specific molecules are taken in after they \_\_\_\_ to a receptor
2. exocytosis
movement of substances \_\_\_\_ of a cell
\_\_\_\_\_\_ energy
A

substances
particulate matter
fluid
bind

out
requires

37
Q

the membranes main job is to _____ ____ _______ and keep the cell ________.
it is selectively ________.
some marterial can _____ enter and exit the cell, others can’t.

A

define cell boarders, functional
permeable
freely

38
Q

membrane _____ the nature of its interaction with its environment.
cell has _______ that allow other cells to recognize it. this plays a roll in self vs nonself ________.
inter gram proteins act as _______ processing activators.
HIV is…

A

determines
markers, distinction
intercellular
human immunodeficiency virus

39
Q

the plasma membrane was found in _____
chemical components were found in ____
principle components were ____ and ______

A

1890
1915
lipids, proteins

40
Q

in ____ davson and danielli proposed the plasma membrane structure
first model that was ______ accepted
based on ____-_____ appearance
theorized structure resembled a ________
_____ were the bread, _____ were the filling
plasma membrane ranges from _-__ mm
phospholipids are made up of _____, two ____ _____ and a ______ linked head group
cholesterol is four fused ______ rings. they’re situated beside __________.
protein make up __%, lipids make up __% and carbs make up __%
amphiphilic means-
plasma membrane includes…

A
1935
widely 
rail road
sandwich
proteins, lipids
5,10
glycerol, fatty acids, phosphate 
carbon
phospholipids
50, 40, 10
nonpolar, dual-loving 
phospholipids, cholesterol, proteins, and carbohydrates
41
Q

integral proteins ____ completely into the membrane structure.
peripheral proteins are on the _____ and _____ surface, and attach to integral proteins and phospholipids.
both may serve as ______

A

integrate
exterior and interior
enzymes

42
Q

carbs are the _____ major plasma membrane component

bound to ______ or ______.

A

third

proteins, lipids

43
Q
component
phospholipid
cholesterol 
integrins
peripheral proteins
carbohydrates
A
location 
main membrane fabric
attached between phospholipids/layers
embedded in phospholipid layer
bilayers inner and outer surface
attached to proteins outside membrane layer
44
Q

plasma membranes are ___________

A

asymmetric

45
Q

factors that affect diffusion

  1. extent of the ______ gradient
  2. _____of molecules diffusing
  3. higher ________ increases energy and movement
  4. as ______ increases, _____ rate decreases
  5. nonpolar ______ material from ass through membrane easier
  6. increased ______ ______ increases the diffusion rate
  7. greater the _______ a surface must travel, the slower the diffusion rate
A
  1. concentration
  2. mass
  3. temperature
  4. density
  5. soluble
  6. surface area
  7. distance
46
Q

tonicity is how an ______ solution can change a cells volume by affecting osmosis

A

extracellular

47
Q

plasmolycsis is when the cell membrane _______ from the cell wall and constricts the cytoplasm

A

detaches