intro to cell mem transport

Question 1

what do the dendrites do

Answer 1

capture signals of other adjacent neurons

Question 2

what is an axon

Answer 2

long tube that transmits info

Question 3

how does the cns communicate

Answer 3

with action potentials

Question 4

where and when does the reception of info occur

Answer 4

at the level of dendrites and right after the synapse

Question 5

what different influences are considered for the treatment of info

Answer 5

inhibition (-) and excitation (+)

Question 6

what structures transmits info

Answer 6

axon

Question 7

from what neuron to what neuron does the signal direcxtion go

Answer 7

pre synaptic to post synaptic

Question 8

what is proprioception

Answer 8

sense of body mvt provided thru cell mem exchange

Question 9

why is an injury painful (explain what happens)

Answer 9

receptors have a deformation in their mem that will lead to an exhange of ions that will result in pain being felt because the signal has reached the brain

Question 10

what makes up the lipid bilayer

Answer 10

lipid barrier
proteins
carbohydrates

Question 11

what is the lipid bilayer permeable to

Answer 11

lipid-soluble substances(O, N, CO2, alcohol)

Question 12

what is the lipid bilayer impermeable to

Answer 12

water and water soluble substances (ions, glucose, urea)

Question 13

what does the lipid bilayer do

Answer 13

it forms a barrier to protect the neurons and to maintain a certain level of electrical potential

Question 14

what are the two types of membrane proteins and what do they both transport

Answer 14

integral proteins and peripheral proteins transport water-soluble substances across the cell membrane

Question 15

where are integral proteins on the membrane and what do they act as

Answer 15

protrude thru mem
act as pores & channels and substance carriers

Question 16

where are peripheral proteins on the membrane and what do they act as

Answer 16

attached to one side of the mem (often attached to integral prot) much smaller than integral prot
acts as enzymes (regulates cell mem) and controller of transport through channels

Question 17

what are the 2 basic processes of transport and which requires E

Answer 17

diffusion (no E) and active transport (E)

Question 18

what are the two types of diffusiom

Answer 18

simple (lipid bilayer or channel prot) or facilated (carrier proteins)

Question 19

what are the two places mol move thru in simple diffusion (which passes bigger mol)

Answer 19

interstices of lipid bilayer for lipid soluble substances
and thru protein channels for water and lipid insoluble mol (bigger mol)

Question 20

what are the characteristics of selective permeability of ions or mol with diffusion thru protein channels

Answer 20

diameter of channel
shape of channel
diameter of substance (K+ > Na+)
nature of electrical charges along the surface of the channel

Question 21

what are the different types of gates

Answer 21

voltage gating channels and ligand- gating channels

Question 22

what do voltage gating channels respond to and what do they participate in

Answer 22

respond to electrical potential (changes will make the gate open or close)
participate in generation of a.p

Question 23

what do chemical gating channels respond to and what do they participate in

Answer 23

respond to binding of another molecule with the channel
participate in synaptic transmission (receptors)

Question 24

what are the steps of facilitated diffusion

Answer 24

mol diffuses by using a specific carrier protein => mol enters the pore and binds to binding point (connection btw carrier prot and transported mol.) of protein => a conformational change occurs so that the pore opens to the opposite side => mol is released

Question 25

what is the role of facilitated diffusion

Answer 25

transporting large mol like glucose and amino acids

Question 26

what is the diffusion rate in simple diffusion

Answer 26

proportional to the [ ] of transported substance (the higher the [ ] the faster the rate of diffusion)

Question 27

what is the diffusion rate in facilitated diffusion

Answer 27

not proportional to the [ ] of the transported substance (diffusion rates approaches a max as the [ ] of the diffusing substance increases)

Question 28

why is there a plateau in the diffusion rate of facilitated diffusion

Answer 28

bc carrier prot become saturated and only one can pass at a time

Question 29

what are the two factors that affect net rate of diffusion

Answer 29

-[ ] diff (net mvt of mol from high [ ] to low [ ]; [ ]gradient) -electrical pot diff (electrical charge of ions cause them to move thru the mem even tho no [ ] diff exists to cause mvt) (a [ ] diff of the ions will be developed in the direction opposite to the electrical pot)

Question 30

what will negative charges do if positive inside and

Answer 30

will go inside if its more positive if started outside

Question 31

why do mol or ions need energy for active transport across the mem tru a carrier prot

Answer 31

bc they are going against their [ ] and/or electrical gradient (flow is against the gradient so need to push harder)

Question 32

what are the substances that can be transported thru mem by active transport and how can these substances also be transported by

Answer 32

Na+, K+, Fe2+, H+, Cl-, urate ions, sugars and amino acids also transported by passive transport thru the process of diffusion depending on the need

Question 33

what are the 2 types of active transports and what is the source of E used for both

Answer 33

primary active transport : ATP (used to activate pump) secondary active transport: E is driven from the [ ] gradient of one of the 2 transported sub

Question 34

what is an example of primary active transport and what gets moved in and out of the cell

Answer 34

Na+/K+ pump 3 Na+ go out and 2 K+ go in (against [ ] gradient)

Question 35

what is the role of the Na+/K+ pump and what is the values at rest and how much E does it require

Answer 35

maintains [ ] diff across cell mem (more Na+ outside and more K+ inside negative electrical potential inside the cell at rest (always negative but charge depends on the type of cell) requires 1 to 2/3 of the cell's E

Question 36

what cause the conformational change in the Na+/K+ pump

Answer 36

the enzymatic ATPase activity

Question 37

what is the net charge of the Na+/K+ pump

Answer 37

increase of 1 positive charge outside; electrogenic (transfer of 1 net + charge out of the cell)

Question 38

how many sub are transported in secondary active transport and where does the E come from

Answer 38

2: principal and co-transported E comes from the [ ] gradient of the principal sub

Question 39

what are the 2 forms of secondary active transport and what is the main goal of secondary active transport

Answer 39

symport: the 2 sub move in same direction antiport: the 2 sub move in opposite directions Maintain homeostasis in the cell

Question 40

what would be an example of symport s.a.t and where is the binding site for both

Answer 40

sodium (principal) and glucose(cotransported) both bind on the carrier prot in the cell mem

Question 41

what causes both Na and glucose to move together into the cell and when does that process start

Answer 41

the energy gradient of the Na+ (driving force and provides gradient E) once both sub are attached to the carrier prot a conformational change occurs

Question 42

where are the principal and counter-transported sub located in relation to the mem in antiport of s.a.t

Answer 42

opposite sides of the mem

Question 43

where would Na+ bind and Ca2+ bind and where would they go when bound in antiport of s.a.t

Answer 43

Na+ binds on the ext side of the prot and Ca2+ (counter-transported sub) binds on the int side w the gradient E, Na+ goes from out to inside and Ca2+ goes from inside to outside

Question 44

Na+-Ca2+ antiport occurs thru ____ ___ ____ mem

Answer 44

almost all cell

Question 45

Na+-H+ antiport occurs in several ____ especialltyimportant in the prox tubules of the kidney

Answer 45

tissues

Question 46

mol are constantly kept with ___ [ ] inside and outside of cell and why is it important

Answer 46

unequal important for the optimal functioning of the cell

Question 47

what is the charge of extracellular fluid and what is it high in (AT REST)

Answer 47

postively charges and high in Na+, Ca2+ and Cl-

Question 48

what is the charge of intracellular fluid and what is it high in (AT REST)

Answer 48

negatively charged and high in K+, Mg2+, proteins