chapter 5 structure and function plasma membranes

Question 1

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

Answer 1

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

Question 2

4 components of cell membrane

Answer 2

phospholipid bilayer
transmembrane protein
interior protein network
cell surface markers

Question 3

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

Answer 3

phospholipids, cholesterol, and proteins

carbohydrates

Question 4

phospholipid structure consists of

Answer 4

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

Question 5

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

Answer 5

inside

both

Question 6

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 ______.

Answer 6

hydrophilic, hydrophobic
head, glycerol
saturated, unsaturated
inward

Question 7

membrane proteins

Answer 7

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

Question 8

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

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

Answer 8

interior

both

Question 9

the transmembrane domain _____ the lipid bilayer

hydrophobic amino acids arrange into a ______

Answer 9

spans

helice

Question 10

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

Answer 10

alpha-helices

beta-sheets

Question 11

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

Answer 11

CD4

Question 12

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.

Answer 12

molecules 
energy 
concentration 
movement of molecules from high to low concentration
same

Question 13

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

Answer 13

repels

nonpolar, equal

larger

Question 14

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

Answer 14

high, gradient

Question 15

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

Answer 15

facilitated, channel proteins

Question 16

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

Answer 16

hydrophobic interior, polar, nonpolar

Question 17

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

Answer 17

equal

small, larger

Question 18

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

Answer 18

protein so

Question 19

channel proteins are

carrier proteins

Answer 19

hydrophilic channel (when open)

bind themselves to molecules they assist

Question 20

membrane is _____ permeable

Answer 20

selectively

Question 21

___ ______ allow passage of ions.

Answer 21

ion channels

Question 22

gated channels:

Answer 22

open or close in response to stimulus message

Question 23

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

Answer 23

either
voltage
open or closed

Question 24

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

Answer 24

aqueous
solvent
solute

Question 25

osmosis is

Answer 25

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

Question 26

hypertonic have a _____ solute concentration | hypotonic has a ____ solute concentration

Answer 26

higher | lower

Question 27

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

Answer 27

isotonic

Question 28

aquaporins _______ osmosis

Answer 28

facilitate

Question 29

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

Answer 29

``` force swell, pressure counter balances burst isotonic ```

Question 30

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

Answer 30

``` execution isosmotic regulation concentration circulate turgor pressure ```

Question 31

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

Answer 31

ATP low to high highly selective carrier proteins

Question 32

types of carrier proteins

Answer 32

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

Question 33

the ____-_____ _____ directly uses ATP for active transport

Answer 33

sodium-potassium pump

Question 34

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

Answer 34

3,2 against confirmation ions

Question 35

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

Answer 35

indirectly diffusion symporter glucose

Question 36

``` 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 ```

Answer 36

substances particulate matter fluid bind out requires

Question 37

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

Answer 37

define cell boarders, functional permeable freely

Question 38

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…

Answer 38

determines markers, distinction intercellular human immunodeficiency virus

Question 39

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

Answer 39

1890 1915 lipids, proteins

Question 40

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…

Answer 40

``` 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 ```

Question 41

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 ______

Answer 41

integrate exterior and interior enzymes

Question 42

carbs are the _____ major plasma membrane component | bound to ______ or ______.

Answer 42

third | proteins, lipids

Question 43

``` component phospholipid cholesterol integrins peripheral proteins carbohydrates ```

Answer 43

``` location main membrane fabric attached between phospholipids/layers embedded in phospholipid layer bilayers inner and outer surface attached to proteins outside membrane layer ```

Question 44

plasma membranes are ___________

Answer 44

asymmetric

Question 45

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

Answer 45

1. concentration 2. mass 3. temperature 4. density 5. soluble 6. surface area 7. distance

Question 46

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

Answer 46

extracellular

Question 47

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

Answer 47

detaches