5.5-5.11 Quiz/Vocab

Question 1

what do membrane proteins do?

Answer 1

specialize

Question 2

in what ways to membrane proteins specialize?

Answer 2

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

Question 3

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

Answer 3

for membranes to allow some but not all substances to pass

Question 4

what is the membrane permeable to?

Answer 4

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

Question 5

what is the bilayer impermeable to?

Answer 5

to charged ions and most large polar molecules

Question 6

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

Answer 6

yes

Question 7

are hydrophobic non polar molecules permeable?

Answer 7

yes

Question 8

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

Answer 8

yes

Question 9

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

Answer 9

NO

Question 10

are ions and electorally charged molecules permeable?

Answer 10

NO

Question 11

How do impermeable substances cross the membrane?

Answer 11

via transport proteins (carrier and channel)

Question 12

what are carrier proteins?

Answer 12

proteins that change shape and transfer molecules

Question 13

What does carrier mediated transport transfer?

Answer 13

solutes

Question 14

what are the two forms of carrier-mediated transport?

Answer 14

active and passive transport

Question 15

what do transfer proteins do?

Answer 15

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

Question 16

what is diffusion?

Answer 16

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

Question 17

what is concentration gradient?

Answer 17

when particles in a liquid or gas are unevenly distributed

Question 18

how does diffusion move across concentrations?

Answer 18

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

Question 19

what is a membrane gradient?

Answer 19

potential energy capable of doing work

Question 20

how is the rate of diffusion determined?

Answer 20

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

Question 21

what is dynamic equilibrium?

Answer 21

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

Question 22

what is simple diffusion?

Answer 22

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

Question 23

what is facilitated diffusion?

Answer 23

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

Question 24

what do channel proteins do?

Answer 24

form hydrophilic channels where specific ions move down their electrochemical gradients

Question 25

what is osmosis?

Answer 25

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

Question 26

what is osmotic pressure?

Answer 26

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

Question 27

what is an isotonic solution?

Answer 27

no net movement of water molecules

Question 28

what is a hypertonic solution?

Answer 28

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

Question 29

what is a hypotonic solution?

Answer 29

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

Question 30

what is tonicity?

Answer 30

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

Question 31

when cells shrinks in hypertonic solutions?

Answer 31

crenation (animals), and plasmolysis (plants)

Question 32

when cells swell in hypotonic solutions?

Answer 32

hemolysis (animals), turgor pressure (plants)

Question 33

what is active transport?

Answer 33

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

Question 34

what is indirect active transport?

Answer 34

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

Question 35

what energy source does a NA-K pump use?

Answer 35

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

Question 36

What does ATP produce?

Answer 36

a concentration gradient

Question 37

what is a cotransport system?

Answer 37

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

Question 38

what does cotransport do?

Answer 38

indirectly provide energy for active transport

Question 39

what is exocytosis?

Answer 39

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

Question 40

how does endocytosis import material?

Answer 40

through phagocytosis, pinocytosis or receptor-mediated endocytosis

Question 41

what is phagocytosis?

Answer 41

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

Question 42

what is pinocytosis?

Answer 42

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

Question 43

what is receptor mediated endocytosis?

Answer 43

specific molecules combine with receptor proteins in the membrane

Question 44

what do junctions do?

Answer 44

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

Question 45

what types of junctions are there?

Answer 45

anchoring, tight, gap, and plasmodesmata

Question 46

what do anchoring junctions do?

Answer 46

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

Question 47

what are two types of anchoring junctions?

Answer 47

desmosomes, and adhering junctions

Question 48

what do tight junctions do?

Answer 48

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

Question 49

what do gap junctions do?

Answer 49

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

Question 50

what does plasmodesmata do?

Answer 50

allow for movement between the cells