I was browsing through Pinterest and saw a really interesting image that came from http://www.nature.com that gave a timeline about the different ways we taste and the discovery of those ways. I was really surprised that a lot of our taste receptors were found pretty recently! I always think its pretty neat to relate history and biology and see the background of the discoveries, it puts a new perspective on science and gives a lot of insight to things you might not otherwise consider.
Although many people think that the different tastes, salty, sour, sweet and bitter, are recognized in different areas of the tongue, it has actually been shown that tastes can actually be sensed from all parts of the tongue, with greater recognition on the sides. Bitterness is usually stronger tasting on the back of the tongue which is thought to be an evolutionary way to be able to spit out poisons or spoiled foods before swallowed.
Where tastes come from:
Sour: Hydrogen ions released from acidic foods like lemons provide that sour taste that makes you squinch up your face!
Salty: Sodium Chloride or other mineral salts like potassium chloride and magnesium chloride give the salty taste
Sweet: most sweet foods are high in sugar! Sugar and other derivatives like lactose help make your foods and candy sweet. certain amino acids and some alcohols can also be perceived by your senses as sweet!
Bitter: isn’t it weird when you think something is so bitter that you can’t even eat it, but your friend has no problem with it at all? There is still research being done on this as there are many theories as to why. It’s said that the bitter sensation could have developed in order to protect our bodies from poisons and other harmful things that develop this taste.
What about everything else?! There’s another taste called umami. I know, it sounds like a delicious chinese chicken and vegetable plate, but it’s not. Umami is described as savory and the taste comes from glutamic or aspartic acids.
Terms to Know:
Papillae: lingual papillae are small protuberances found on the tongue. Three forms of lingual papillae, fungiform, foliate and circumvallate, contain taste buds while the fourth form, filiform, helps detect texture.
Receptor: a molecule, usually protein, or cell, that responds to an external stimulus and in response, causes a change in shape/function of a cell.
Stem Cell: a class of cells that are able to differentiate into specialized cells.
Ion-channel: pore shaped proteins that allow the flow of ions across the membrane of a cell
Ion: a particle with a negative electrical charge
Proton: a particle with a positive electrical charge
Acid: a compound that can donate a Hydrogen ion to another compound
Carbon Dioxide: a chemical compound composed of two oxygen atoms covalently double bonded to a carbon atom
Amino Acid: organic compound composed of an amine (NH2) functional group, a carboxylic acid (COOH) functional group, and another side group that is specific to each amino acid.
Epithelium: the type of animal tissue that line hollow organs and glands
Gland: an organ capable of secreting a substance into a different part of the body for a specific use