C12 membrane transport Flashcards
move molecules from one side of membrane to other using conformational change
carrier proteins
small pore that allows specific ions to flow by diffusion
channel proteins
Na+ is kept in high concentration (inside/outside) cell
outside (extracellular)
K+ is kept in high concentration (inside/outside) cell
inside (intracellular)
Cl- is kept in high concentration (inside/outside) cell
outside
? transport moves molecules down a concentration gradient
passive
? transport moves molecules against a concentration gradient
active
facilitated diffusion
passive transport specific for the molecule
function of insulin
stimulates glucose uptake in muscle and fat cells
Humans have ? different glucose transporters
5
insulin secretion is triggered by ?
increases in blood sugar
the cytoplasmic side of the plasma membrane us usually kept (negative/positive)
negative
the electrical gradient is derived from ?
the membrane potential
the chemical gradient is derived from ?
relative concentration of individual charged molecule
The ? pump is responsible for the membrane potential in animal cells
Na+,K+ ATPase
The Na+,K+ ATPase pumps ? Na out and ? K in
3,2
P-type pumps catalyze ?
autophosphorylation
The Na/glucose transporter is an example of (symport/antiport)
symport
The Na+/H+ exhanger is an example of (symport/antiport)
antiport
principal passive glucose uniport
GLUT 2
insulin-regulated glucose transporter
glut 4
function of Ca++ ATPases
maintain very low intracellular CA++ concentration
Intracellular Ca++ can be used for ?
signalling
Plants, fungi and bacteria rely primarily on gradients from ? to drive secondary transport
H+
Three ways to gate ion channels
voltage, ligand, stress
the acetyl choline receptor is a ? channel
na+
channels spontaneously fluctuate between open and closed? t/f
true
channel that establishes resting potential of -70mV
K+
Depolarization of nerve cells is a result of ? (2)
stimulation followed by Na+ flow into cell
Opening of Na+ channel in nerve cell occurs around this membrane potential
-50mV
Na+ channel in nerve cells closes around this membrane potential?
+50mV
? flow out of cell repolarizes cell
K+
The Na+ channel is ? gated
voltage
? cells wrap nerve axons to provide electrical insulation
schwann
Is transmitted the length of the axon without additional energy input
action potential
synapse
junction between two neurons where electrical signal is converted to neurotransmitter
? channel triggers release of neurotransmitter
Ca++
novacain function
blocks Na+ ion channels. prevents action potentials and therefore pain.
nerve gas function
inhibitor of acetylcholine esterase. acetylcholine accumulates and keeps nerve on.
alpha-bungarotoxin function
inhibitor of acetylcholine receptor. nerve cannot be stimulated by neurotransmitter
Botox function
inhibits neurotransmitter release. muscles cannot be stimulated
Prozac
increase serotonin levels
provides info for how individual ion channels behave
patch-clamp recording
oubain function
inhibiting na,k pump, inhibits glucose uptake by epithelial cells
