Sensory Transduction

Question 1

binding sites of odorant molecules

Answer 1

helices 4, 5

Question 2

what is combinatorial mechanism?

Answer 2

odorant activates a number of receptors and almost every receptor is activated by more than one odorant

allows small array of receptors to distinguish a vast number of odorants

Question 3

quinine

Answer 3

bitter

Question 4

glutamate

Answer 4

umami (neurotrasmitter)

AA present in protein-rich foods and MSG

Question 5

in olfaction, what contains the odorant-binding protein receptors?

Answer 5

cilia

Question 6

in taste, what contains the taste receptors?

Answer 6

microvilli (finger-like projections)

Question 7

how are salty tastants detected?

Answer 7

passage through AMILORIDE-SENSITIVE SODIUM CHANNELS

Question 8

how many subunits in amiloride-sensitive na channels?

Answer 8

4 subunits

2 hydrophobic membrane-spanning domains
intracellular amino & carboxyl termini
extracellular region w/ conserved cysteine-rich domains

Question 9

what blocks the transmembrane current generated by passage of Na+ through amiloride-sensitive channel?

Answer 9

AMILORIDE

Question 10

what is the receptor for glutamate?

Answer 10

metabotropic glutamate receptor

Question 11

rod receptor

Answer 11

rhodopsin

Question 12

what is opsin?

Answer 12

a 7TM protein

Question 13

absorbs maximally at 370 NM

Answer 13

free retinal

Question 14

absorbs at 440NM

Answer 14

unprotonated schiff base

Question 15

absorbs at 500 NM

Answer 15

protonated schiff base

Question 16

a capsaicin receptor

Answer 16

vanilloid receptor 1 (VR1)