lecture 11 membrane transport

Question 1

cell membranes are ________ permeable

Answer 1

selectively

Question 2

review worksheet about what solutes than can cross a phospholipid bilayer

Answer 2

ok

Question 3

what type of molcules pass directly between lipids forming the membrane

Answer 3

small hydrophobic and small uncharged polar molcules

Question 4

small molecules that cannot use simple diffusion to cross a cell membrane use what

Answer 4

transporter proteins and facilitated diffusion

Question 5

what is facilitated diffusion

Answer 5

diffusion with help (from the transporter protein

Question 6

what is faciliatetd diffusion mediated by

Answer 6

channel prpteins and carrier proteins

Question 7

what is channel protein mostly used by

Answer 7

ions

Question 8

what are carrier proteins mostly used by

Answer 8

other small solutes

Question 9

how do channel proteins work

Answer 9

make tunnel to pass through membrane

Question 10

how do carrier proteins work

Answer 10

chnage coformation allow their solute to cross the membrane

Question 11

most channel proteins are what

Answer 11

gated, which means they open and close in response to cellular conditions

Question 12

examples gated channel protein

Answer 12

-binding of ligand
-change in electrical gradient
-mechanical trigger
-light activation

Question 13

what do diffusion rates of ions through ion channels depend on

Answer 13

electrochemical gradients

Question 14

typical electrochemical gradient of cellular conditions

Answer 14

membrane potential negative inside

Question 15

active transport

Answer 15

movement of solutes against their concentration gradient

Question 16

what does active transport require

Answer 16

energy, making system more organized

Question 17

what is concentration gradient in terms of ions

Answer 17

electrochemical gradient

Question 18

examples of active transport

Answer 18

coupled transport, ATP driven pump, light driven pump

Question 19

coupled trasnport refers to

Answer 19

protein

Question 20

what is coupled trasnport

Answer 20

two moleqs cross the membrane at some point in time but one moves positively and releases energy

Question 21

what should you think when you hear pump

Answer 21

energy is required (active transport)

Question 22

is Na+/K+ ATPase an example of coupled trasnport

Answer 22

no

Question 23

sodium potassium pump use what type of transport

Answer 23

active

Question 24

how does sodium potassium pump move

Answer 24

uses 1 ATP to move 3 Na+ out and 2 K+ in

Question 25

what does sodium potassium pump hydrolyze

Answer 25

hydrolyzes ATP to make ADP

Question 26

watch video on it

Answer 26

ok

Question 27

what is the sodium potassium pump chiefly responsible for

Answer 27

maintaining the membrane potential of cells (the difference in charge on either side of a cell membrane)

Question 28

importance of sodium potassium pump and the Na+ gradient

Answer 28

it drives the active transport of many other solutes across the membrane

Question 29

what does Na+ influx with sodium-potassium pump begin

Answer 29

-an action potential in neurons (how a neuron relays a neural impulse) -begins muscle contraction by muscle cells

Question 30

what do you need for influx with sodium-potassium pump

Answer 30

Na+ gradient

Question 31

what is coupled transport also called

Answer 31

co-transport

Question 32

what is coupled trasnport

Answer 32

the electrochemical gradient of one molecule drives the transport of another molecule against its concentration gradient

Question 33

how many molecules cross the membrane with coupled transport

Answer 33

two

Question 34

describe how the two molecules move with coupled transport

Answer 34

1)one cross by passive transport: releases energy (exergonic process) 2)crosses by active transport: requires energy (endergonic process)

Question 35

what are two molecules that go into cell via coupled trasnport

Answer 35

glucose and Na+ -diffusion of Na+ (passive transport) provides energy to pump glucose against its concentration gradient 9active transport)

Question 36

bulk trasnport

Answer 36

moves larger molecules (polymers) in and out of a cell and depend son membrane fusion and budding

Question 37

what type of molecules are moved by passive and active transport

Answer 37

small molecukes

Question 38

exocytosis

Answer 38

large molecules are secreted when a vesicle fuses with the plasma membrane

Question 39

endocytosis

Answer 39

large molecules are taken in when the plasma membrane pinches inward, forming a vescile

Question 40

what type of materials are transferred by exocytosis and endocytossi

Answer 40

larger materials acorss cell membrane

Question 41

where do materials taken up by endocytosis usually end up

Answer 41

lysosome

Question 42

what are proteins and polysaccharides made by ER and Golgi secreted by

Answer 42

the cell via exocytosis

Question 43

what is budding and fusion of vesicles critical for

Answer 43

the synthesis and delivery of secreted and membrane proteins

Question 44

what are three forms of endocytosis

Answer 44

-phagocytosis -pinocytosis -repceptor-meditated endocytosis

Question 45

what is phagocytosis chiefly done by

Answer 45

white blood cells

Question 46

phagocytosis

Answer 46

cell reaches out extensions that wrap around phagosomes (vacuoles)

Question 47

do pinocytosis and recepto mediated endocytosis grab anything

Answer 47

no, but it reaches down invaginating and ingested materials get stuck in it.

Question 48

with what form of endocytosis does cholesterol enter cell

Answer 48

receptor mediated endocytosis

Question 49

summarize passive trasnport

Answer 49

high -> low [] movement -does not use [] -moves ions

Question 50

summarize active tranport

Answer 50

-against [] gradient -uses energy -always requires protein

Question 51

what do passive and active transport both involve

Answer 51

-movement of molecules across/through the membrane -proteins may be involved

Question 52

what is [] gradident

Answer 52

diff in [] in 2 areas/2 regions separated by a membrane

Question 53

are all solutes ions

Answer 53

no

Question 54

what are ways active transport can obtain energy

Answer 54

-ATP driven pump -coupled transport -passive transport