module 4 - cell membrane transport

Question 1

what do cell membranes contain

Answer 1

specialized membrane protein and transport proteins

Question 2

what does membrane transport proteins facilitate?

Answer 2

passage of small water soluble molecules

Question 3

what are lipid bilayers impermeable to ?

Answer 3

ions and most uncharged polar molecules

Question 4

what determines diffusion rate

Answer 4

molecule’s size and solubility

Question 5

diffusion

Answer 5

dye molecules move to become evenly distributed (goes from initial –> diffusion —> final)

Question 6

what are the inorganic ions for cells?

Answer 6

Na, K, Ca, Cl and H

Question 7

which inorganic ion is most abundant outside cell

Answer 7

Na+

Question 8

which inorganic ion is most abundant inside cell

Answer 8

k+

Question 9

how is a voltage difference created

Answer 9

small excess of + or - charge on 2 sides of plasma membrane

Question 10

membrane transport is mediated by?

Answer 10

2 classes of membrane proteins

Question 11

what creates membrane potential

Answer 11

activity of membrane transport proteins

Question 12

what transfers small organic molecules or inorganic ions?

Answer 12

transporters

Question 13

how do substances pass by?

Answer 13

channels for pores and passes by diffusion

Question 14

downhill movement

Answer 14

high conc to low conc (no driving force)

Question 15

uphill movement

Answer 15

requires energy - active transport

Question 16

what influences the passive transport of charged solutes?

Answer 16

conc gradient and membrane potential

Question 17

for an uncharged molecule, movement is determined by

Answer 17

its conc gradient

Question 18

for an charged molecule, movement is determined by

Answer 18

exert forces

Question 19

osmosis is

Answer 19

diffusion and can modify shapes of cells

Question 20

what is responsible for water reabsorption

Answer 20

aquaporin

Question 21

what do passive transporters change

Answer 21

conformation to mediate transport

Question 22

important example of passive transporter?

Answer 22

glucose transporter

Question 23

how does glucose transporter work?

Answer 23

glucose binds the protein and changes the shape

Question 24

active transport

Answer 24

movement of molecules against their conc

Question 25

active transporters

Answer 25

transmembrane proteins responsible for active transport

Question 26

what are the 3 types of proteins for active transport?

Answer 26

uniporter, symporter, antiporter

Question 27

uniporter?

Answer 27

one in one direction

Question 28

symporter

Answer 28

2 diff substances in same direction

Question 29

antiporter

Answer 29

2 diff substances in opposite directions

Question 30

what are coupled transporters

Answer 30

symporters and antiporters

Question 31

what are the 3 diff energy sources used in active transport

Answer 31

ATP, electrochemical gradient and light

Question 32

Ca2+ to ??

Answer 32

Ca2+

Question 33

Na+ to ???

Answer 33

energy

Question 34

what is a primary active transport

Answer 34

na+ transporter

Question 35

what is secondary active transporters

Answer 35

coupled transporters

Question 36

what are involved in glucose transfers

Answer 36

active and passive transporters

Question 37

how do large molecules enter and leave?

Answer 37

in is endocytosis
exp is exocytosis

Question 38

vesicle fusion

Answer 38

release of large and small molecules

Question 39

which molecules are too large to pass through

Answer 39

proteins, polysaccharides and nucleic acids

Question 40

what are the 3 types of endocytosis?

Answer 40

receptor-mediated

pinocytosis

phagocytosis

Question 41

how are electrical charges balanced outside of cell

Answer 41

Na+ ions by Cl- ions

Question 42

how are electrical charges balanced inside of cell

Answer 42

K+ by negative charges of organic molecules

Question 43

what creates a membrane potential

Answer 43

difference in concentration of inorganic ions

Question 44

how do inorganic ions move?

Answer 44

ion channels create openings for passive movement

Question 45

what are ion channels ?

Answer 45

narrow and highly selective

Question 46

what characteristics distinguish ion channels from pores?

Answer 46

ion selectivity and open/closure state

Question 47

which ion channels are gated

Answer 47

ligand-gated

voltage-gated

mechanically-gated

Question 48

what are ion channels responsible for?

Answer 48

electric signal generation and transmission in neurons

Question 49

what is recorded are changes in membrane potential

Answer 49

activities of neurons

Question 50

depolarized cell membranes

Answer 50

voltage Na+ open

Question 51

hyper polarized cell membranes

Answer 51

chemically gated K+

Question 52

what is action potential

Answer 52

rapid change

Question 53

what do action potentials do?

Answer 53

travel and jump along axons in 1 direction

Question 54

synapses

Answer 54

signal unique junctions

Question 55

synaptic cleft

Answer 55

post and presynaptic cells

Question 56

neurotransmitters receptors are ??

Answer 56

ligand-gated ion channels

Question 57

which gates are responsible for muscle contractions?

Answer 57

ligand

Question 58

mechanically-gated ion

Answer 58

channels in auditory hair cells allow us to hear