Taste buds are structures on our tongue
s that hold taste cell
s, which give rise to the sense of taste
. Each taste bud holds fifty to one-hundred cells, and taste buds may hold cells for all of the five kinds of taste
. The classic diagram
showing what taste each region of the tongue is sensitive to is, therefore, incorrect (or at least overgeneralize
d). Nerve bundle
s come out of the base of each taste bud, and each individual taste cell connects to a single nerve
The five types of cells found on taste buds are:
Salty: these cells react with substances which release sodium ions (Na+), and are thus salty.
Bitter: there are around eighty different genes (with corresponding proteins) that sense different bitter molecules.
Sour: these react with protons (H+) released by acidic -- therefore sour -- substances.
Sweet: another that relies on proteins to determine whether a given molecule is sweet.
Umami: cells triggered by the salts of glutamic acid, notably MSG and salts found in seaweed.