transporters

Question 1

describe passive diffusion

Answer 1

substance moves down concentration gradient, no proteins required, small uncharged lipophilic molecules

Question 2

describe facilitated diffusion

Answer 2

substance flows along concentration gradient, proteins required

Question 3

describe primary active transport

Answer 3

carrier protein required, substance flows against concentration gradient, energy provided by ATP hydrolysis, moves molecules or ions

Question 4

describe secondary active transport

Answer 4

carrier protein required, substance flows against concentration gradient, energy provided by ATP hydrolysis, gradient of ion used to couple transport, can be symport or antiport

Question 5

what are the 3 transporter types?

Answer 5

ion transporters and pumps
nutrient/metabolite transporters
neurotransmitter transporters

Question 6

give examples of ion transporters and pumps

Answer 6

Na-K ATPase

Na/Ca exchangers

Question 7

give examples of nutrient/metabolite transporters

Answer 7

glucose, nucleosides

Question 8

give examples of neurotransmitter transporters

Answer 8

monoamines, inhibitory amino acids, excitatory amino acids, ACh, neuroactive peptides

Question 9

how are neurotransmitters removed from the synaptic cleft?

Answer 9

passive diffusion, enzymatic degradation (peptides and ACh), re-uptake by transporters (monoamine and amino acids)

Question 10

transporter protein for dopamine neurons?

Answer 10

DAT

Question 11

transporter protein for noradrenaline neurons?

Answer 11

NET

Question 12

transporter protein for 5-HT neurons?

Answer 12

SERT

Question 13

transporter protein for GABA neurons?

Answer 13

GAT-1

Question 14

transporter protein for ACh neurons?

Answer 14

cholineT

Question 15

how does the glutamate-glutamine shuttle work?

Answer 15

glutamate released from neurones, uptaken into glial cells via EAATs, converted into glutamine by glutamine synthase, glutamine is expoerted from glia and taken up into neurones where it is converted into glutamate by glutaminase.

Question 16

what do the vesicular transporters VMAT-1 and VMAT-2 transport?

Answer 16

vesicular amine transporters - 5-HT, dopamine, noradrenaline, histamine

Question 17

what does the vesicular transporter VAchT transport?

Answer 17

acetylcholine

Question 18

what does the vesicular transporter VIAAT transport?

Answer 18

glycine/GABA

Question 19

what do the vesicular transporters Vglut-1, Vglut-2 and Vglut-3 transport?

Answer 19

glutamate

Question 20

features of epilepsy?

Answer 20

recurrent seizures, caused by burst of electrical activity in brain, causes a temp disruption in normal brain messaging

Question 21

what are the transporters in epilepsy?

Answer 21

glutamate and GABA transporters

Question 22

how does tiagabine work as an antiepileptic?

Answer 22

GABA transporter blocker, blocks GABA reuptake so increases levels in synaptic cleft to block seizure initiation

Question 23

how do SSRIs work?

Answer 23

block 5-HT reuptake into neurones, elevate synaptic levels of 5-HT

Question 24

how does fenfluramine work as an appetite suppressant?

Answer 24

increases serotonin levels by promoting reverse transport by the reuptake transporter, disrupts vesicular storage