Quantum Biology: Can we explain olfaction using quantum phenomenon?

TL;DR

This paper reviews the history and challenges of olfaction theories, especially the vibrational theory, and discusses recent experiments on humans and fruit flies that support or challenge this quantum-based explanation.

Contribution

It provides a comprehensive review of olfaction theories and presents new experimental evidence related to the vibrational theory of smell.

Findings

Experiments on humans support vibrational theory

Fruit fly experiments challenge shape theory

Quantum phenomena may play a role in olfaction

Abstract

The sense of smell is an important part of living organisms. It assists with the interaction of the living organism with its environment. The mechanism by which smell is detected and identified is not fully known. Earlier, shape theory was proposed as an explanation for odor perception mechanism. This theory posits that the shape of the odorant must fit in its complementary olfactory receptor for an odor to be identified -- just like key fits in a lock. This theory turns out to have some limitations, thus leading to the proposition of new theory called the vibrational theory of olfaction. In vibrational theory, the nose is regarded as a spectroscope that detects vibration of odorants. However, this happens to be currently controversial and actively debated. In this paper, I will give a review of the history of olfaction, the challenges, and then explain some new experiments (both on human and fruit flies) that support or refute the vibrational theory of olfaction.