odorant

Examples of odorant in the following topics:

• Tastes and Odors

  • Both taste and odor stimuli are molecules taken in from the environment.
  • All odors that we perceive are molecules in the air we breathe.
  • Humans have about 350 olfactory receptor subtypes that work in various combinations to allow us to sense about 10,000 different odors.
  • Compare that to mice, for example, which have about 1,300 olfactory receptor types and, therefore, probably sense many more odors.

• Reception and Transduction

  • Odorants (odor molecules) enter the nose and dissolve in the olfactory epithelium, the mucosa at the back of the nasal cavity .
  • Humans have about 12 million olfactory receptors distributed among hundreds of different receptor types that respond to different odors.
  • It is the variations in their amino acid chains that make the receptors sensitive to different odorants.
  • The receptors are specialized to detect specific odorants, so the bipolar neurons themselves are specialized.
  • When an odorant binds with a receptor that recognizes it, the sensory neuron associated with the receptor is stimulated.

• Plant Defenses Against Herbivores

  • Some metabolites are alkaloids, which discourage predators with noxious odors (such as the volatile oils of mint and sage) or repellent tastes (like the bitterness of quinine).

• Pollination by Insects

  • Many flies are attracted to flowers that have a decaying smell or an odor of rotting flesh.

• Predation, Herbivory, and the Competitive Exclusion Principle

  • (a) The strawberry poison dart frog (Oophaga pumilio) uses aposematic coloration to warn predators that it is toxic, while the (b) striped skunk (Mephitis mephitis) uses aposematic coloration to warn predators of the unpleasant odor it produces.

• Diffusion

  • This is due to the diffusion of odor molecules through the air, from an area of high concentration (the kitchen) to areas of low concentration (your upstairs bedroom).