Social cells 2

Question 1

conc of potassium in cell?

Answer 1

high

Question 2

conc of sodium inside cell?

Answer 2

lower

Question 3

conc of potassium outside cell?

Answer 3

lower

Question 4

CONC of sodium outside cell?

Answer 4

higher

Question 5

conc of chloride and calcium inside cell?

Answer 5

lower

Question 6

conc of chloride and calcium outside of cell?

Answer 6

HIGHER

Question 7

What is involved in passive transport?

Answer 7

diffusion through bilayer
diffusion through protein channels
facilitated diffusion
e.g. steroid hormones fatty acids, oxygen, carbon dioxide

Question 8

facilitated diffusion compared to diffusion?

Answer 8

facilitated transport mechanism is specific
however limited capacity
transport can be affected by competition (number of channels/carriers)

Question 9

2 mechanisms of active transport?

Answer 9

primary active transport
secondary active transport

Question 10

secondary sctive transport

Answer 10

TWo being moved at once and the difference in energy is stored

Question 11

primaru?q

Answer 11

WILL utilise atp

Question 12

secondaru?

Answer 12

will not utilise ATP

Question 13

why do we need ion pumpks?

Answer 13

becaise we have a lot of ion leakagfe so we need a process that replenishes them and stops this and creates a gradient for the resting potential

Question 14

type of ion pumps?

Answer 14

uniporter, symporter, antiporter

Question 15

what can pumps do?

Answer 15

they can transport ions against their concs gradients e.g. sodium (primary active transport)

Question 16

sodium-potassium primary active transport?

Answer 16

movement of positive ions out of channel out of the cell against conc gradient

Question 17

glucose pump example of?

Answer 17

secondary active transport

Question 18

describe the glucose pump?

Answer 18

coupled to sodium uptake and it uses a co-transporter

Question 19

describe the calcium ion pumop?

Answer 19

calcium need to be kept in cytosol of cells
cytosolic concentration needs to be kept low
use of ATP
some calcium pumps are coupled to sodium
can be primary and secondary active transport

Question 20

what are ion channels?

Answer 20

proteins within the cell membrane and transport specific ions

Question 21

4 types of ion channels?

Answer 21

ligand-gated ion channels
voltage-gated ion channel
leak channels
stretch-activated channels

Question 22

example of ligand gated ion channel?

Answer 22

ion channel coupled receptor

Question 23

binding of ligand?

Answer 23

causes the protein change shape
e.g. nicotinicacetylcholine receptor

Question 24

voltage gated channel?

Answer 24

change in membrane potential of cell
change so the channel is opened
really important for action potentials e.g. ca, cl, na, k

Question 25

leak channels?

Answer 25

pore within membrane and generally always open and maintain resting potential of the cell - always movement of cells along their conc gradients through these

Question 26

stretch activated ion channels?

Answer 26

bilayer model, tether model and indirect gating

Question 27

bilayer model?

Answer 27

swelling due to tension, the channel is essetnially pulled open as the cell gets bigger

Question 28

tether model?

Answer 28

attached to side skeleton of cell or extracellular matrix protein attached to ion channel, any movement or change causes the channel to open due to tension

Question 29

indirect gating?

Answer 29

mechanosensitive portien, capable of sensing any mechanical change in th eextracellulkar matrix
compression of cartilage so change in water content of cell - sensed by mechanoreceptors (mechanosensitive protein)
e.g. calium activated potassium channel

Question 30

importance of ion channels?

Answer 30

muscle paralysis - blocking of voltage gated sodium channels
heart disease - calcium channel blockers
local anaesthetics - lidocane, voltage gated sodium channels - stop feeling by blocking channels

Question 31

what is the resting membrane potential?

Answer 31

this is not the same as an action potential
IT IS THE POTENTIAL ACROSS THE MEMBRANE WHEN THERE IS NO ACTION POTENTIAL BEING PROPAGATED

Question 32

all cells can have a resting membrane potetnail but what can all cells not do?

Answer 32

hpwever not all cel,s can proagate action potential

Question 33

two RMP?

Answer 33

excitable (can propagate action potential) and non-excitavle (cannot)

Question 34

two equations to work out cell’s resting membrane potentials?

Answer 34

Nernst equation
Goldman-Hodgkin-Katz equation (GHK)

Question 35

skeletal muscle (myocytes) membrane potential?

Answer 35

-90mV

Question 36

Synovial fluid (synoviocytes) membrane potentials?

Answer 36

-30mV

Question 37

very negative?

Answer 37

more of a change in membrane potential to give good prooagation of action potential

Question 38

24

Question 39

why -90mV resting membrane potwetnial of skeletal m udcle?

Answer 39

Na/K pump –> 3 Na out and 2 K in
positive charges outside of the cell
Leak channels –> more potassium than sodium
flux of Na larger than efflux of K
results in build up of negative ions on OUTSIDE of cells - helps to attritbute for negative resting membrane potetnail –> action potential

Question 40

pumps?

Answer 40

constantly keeping difference of positive and negative ions either side of membrane

Question 41

indirect gating?

Answer 41

protein that detects a change in the ewxtracellular matrix which resultsin a conformational change in the ion channel

Question 42

conformational change?

Answer 42

change in shape