TASTE    - GUSTATION                                            [home]   [topic page]

The human mouth responds to chemicals through "receptors" on the tongue. Receptors respond to the brain through Ca²⁺ ions being disrupted as they pass through the cell walls. Other sensations are felt in the mouth which are associated with taste. Smell is also connected to taste though this can be misleading.

When a food is taken in to the mouth, vapours sweep into the nose, the texture of the food is sensed and the receptors respond to the chemicals in the food. Saliva actually reacts with foods so a mouthful of food will vary in taste as masticatio proceeds.

Only certain "tastes" exist.

• SALTY - receptor cells "recognise" Na⁺ in particular.

• SOUR - receptor cells respond to protons, H⁺.

• SWEET - receptors bind to glucose and other sugars.

• BITTER - such as quinine.

• UMAMI - certain amino acid tastes - glutamate, aspartate .....

• MONOSODIUM GLUTAMATE - a separate taste which also enhances other tastes. This is not entirely agreed upon as a separate taste.

Excellent sites on the biology of taste are at http://www.sciam.com/2001/0301issue/0301smith.html and www.cf.ac.uk ! In the latter site, a "taste map" of the tongue is shown. This map is totally incorrect. All tastes are sensed all over the tongue.

wine