Why is sugar sweet?
Name: Jonathan J Hoch
How do taste receptors work? To be more specific, what is
the chemical reaction involved in tasting sugar?
Sugar is sweet because when our tongue detects a sugar molecule the
nervous impulse it sends says "sweet". Our tongue detects the sugar
molecule by its shape. The shape fits into a little groove or pit in
the tongues surface, and when this pit is filled it causes the nerve
to fire and send a message to the brain that says "sweet". A lot of
money has been spent developing new molecules that will cause fit in
the little pits and thus tastes sweet, but not be igestible and so have
no calories. Nutrasweet, for instance. However, scientists have been
studying the reasons why the nerve impulse means "sweet" instead of
"salty" or "Yucky" , and I am not sure that they have a definitive
answer, and if they did, whether we would understand it!
Great Answer! Most of our sensation is due to the wiring between the
sensory organ and the brain. Perception on the other hand (end of
Stacey's answer) is carried on by associative areas of the brain and
is very complex. For instance taste + smell = flavor, a derived sense.
This is far more complex than either of the separate senses and this is
the simplest example I can think of. Lots to learn here!
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Update: June 2012