Final answer:
When an odorant molecule binds to a receptor protein, it sets off a signal transduction pathway that generates an action potential, sending a signal to the brain that is interpreted as smell. Humans have around 350 olfactory receptor subtypes that allow us to distinguish a wide array of odors. The brain integrates signals from these receptors to differentiate and identify specific odors.
Step-by-step explanation:
The effect of an odorant molecule binding to any of its target receptor proteins is to initiate a signal transduction pathway. This means that when volatile chemicals, which make up odorant molecules, bind to receptor proteins, they stimulate the sense of smell. Each olfactory receptor neuron has a variety of receptor proteins which can bind to different odorants. This binding triggers a series of biochemical events that amplifies the signal inside the cell.
When the odorant molecule is detected at receptor A, it triggers a signaling cascade. This cascade involves a sequence of changes within the cell that lead to the generation of an action potential. The action potential then travels along the olfactory neuron to the brain where the signal is interpreted as a particular smell. Positive feedback mechanisms can enhance the sensitivity and specificity of the response, contributing to the accurate perception of odors.
In humans, we have about 350 olfactory receptor subtypes that allow us to detect a wide range of different odors. The signal integration by the brain allows us to distinguish between different odors, based on the unique combination of receptors that are activated. The more unique receptors an olfactory system has, the greater its sensitivity and discrimination between odors becomes.