Olfaction and Taste

Question 1

taste buds

Answer 1

sensory receptors on the tongue that directly contact what we ingest
hollow sacs with walls made out of taste receptor cells

Question 2

olfaction

Answer 2

sensory receptors in the nasal cavity that detect aerosolized molecules in the air

Question 3

orthonasal olfaction

Answer 3

the sensing of odor molecules from the outside air

occurs during inspiratory breathing

Question 4

retronasal olfaction

Answer 4

the sensing of odor molecules from the mouth

occurs during expiratory breathing

Question 5

tastant

Answer 5

any substance that can be tasted

Question 6

papillae

Answer 6

tiny bumps on the tongue

each is lined with one or more taste buds

Question 7

salty taste cells

Answer 7

specialized for detecting sodium
salt on the tongue causes the extracellular sodium concentration to increase, resulting in an inward chemical force that pushes sodium into the taste cell to depolarize it
taste receptors are ‘ionotropic’

Question 8

sour taste cells

Answer 8

specialized for detecting acids
express a protein called PKD2L1 that is a non-specific cation channel that is gated by proteins found in acidic compounds
taste receptors are ‘ionotropic’

Question 9

sweet taste cells

Answer 9

specialized for detecting sugars

express a g-protein receptor composed from T1R2 and T1R3 subunits

Question 10

bitter taste cells

Answer 10

specialized for detecting noxious and potentially toxic substances
express a g-protein receptor composed from ~30 different members of the T2R receptor family

Question 11

umami taste cells

Answer 11

specialized for detecting the savory flavor of protein rich foods
express two kinds of g-protein receptors
– metabotropic glutamate receptor activated by the flavor enhancer monosodium glutamate (MSG)
– g-protein receptor composed from T1R1 and T1R3 subunits activated by AAs