Taste Flashcards
What are taste receptors?
Receptor cells that detect only one of the possible tastes. They release neurotransmitters in a graded fashion.
What are the six different categories of taste receptors?
- sweetness
- umami
- bitterness
- saltiness
- sourness
- fat
What do the sugar receptors detect?
The presence of sugar molecules
What is the structure of sugar receptors?
single metabotropic receptors
What is detected by umami taste receptors?
Glutamate/glutamine
What is the structure of an umami taste receptor?
Single metabotropic receptor
What is detected by bitterness taste receptors?
a variety of molecules, mostly those found in toxins
What is the structure of bitterness taste receptors?
- metabotropic receptors
- 50 different types
What taste receptors are naturally pleasurable?
- sweetness
- umami
What taste receptors are naturally aversive?
bitterness
What do saltiness taste receptors detect?
positive ions
What is the structure of saltiness taste receptors?
ion channel that is highly permeable to sodium
What do sourness taste receptors detect?
pH level
What is the structure of the sourness taste receptors?
ion channels that are highly permeable to free protons
What else is detected by the sourness taste receptors?
- carbonation
- astringency
What is detected by fat taste receptors?
fatty acids
What is the structure of fat taste receptors?
metabotropic receptors and fatty acid transporters
What happens when a tasted molecule binds to a taste receptor protein?
- change in membrane potential
What are taste buds?
- cluster of 20 to 50 receptor cells OF THE SAME TYPE
How many different tastes are detected by taste buds?
one
how do taste receptor cells transfer information?
graded neurotransmitter release
how frequently are taste receptor cells replaced?
every ten days
Where are situated the taste buds?
in the grooves of the tongue (many different types of taste buds in one groove)
What determines the fact that a taste is pleasant or not?
The taste bud, not the taste receptor cell
How do animals come to appreciate bitter tastes?
- through acquired taste
- can only be mild bitterness
Why are bitter taste buds aversive?
Bitter tastes are associated with toxins
Are the sour/fat/salt taste receptors aversive or reinforcing?
- depends on the concentration
- learned taste
Where is the gustatory information processed?
In the primary gustatory cortex
How is the primary gustatory cortex organized?
Depends from person to person
Where is the primary gustatory cortex situated?
insula lobe of the cerebral cortex
What is particular of the gustatory capacities of the the cat family?
Cannot taste sugar
