Take look at a teaspoon of water. We know that the liquid is made up of a great many, very small H2O molecules. But how many?
A simple calculation reveals that it is roughly 100 billion trillion molecules. Or put another way, roughly the same number of teaspoons of water that are in all the oceans on Earth.
Why should we care? Yes, molecules are very small. But they are also very powerful because they hold great potential when we make them do the things we want.
LCD displays, vast arrays of pharmaceuticals and plastics for almost any application are all a result of researchers becoming proficient at controlling molecules.
The field of science that focuses on molecules, and looks to relate their behaviour to that in the world around us, is chemistry. The United Nations has officially proclaimed 2011 as the International Year of Chemistry (IYC).
It is a time to celebrate the achievements of chemistry and look at how the discipline will help meet many of our global challenges into the future.
The challenge going forward is to enhance dramatically our ability to control molecules—that is to understand the relationship between structure and function—affording us the ability to make molecules do any of a multitude of things to make our world better.
Let us dream about some possibilities.
Consider the complex molecular machinery that makes up a cell in a living organism. Within a cell, proteins, or sets of proteins, interact with each other to perform a multitude of functions, from transporting nutrients to replication, with great precision to keep the cell alive. Each time one of your cells divides, for example, an intricate set of molecular processes must replicate your DNA, containing three billion base pairs, ?with virtually no mistakes.
In fashioning this elegant machinery, components of which are unique to each individual, nature has clearly understood the relationship between structure and function of molecules.
Imagine some of the problems that we can begin to address if we can achieve a similar understanding: personalized medicine where a drug molecule is specifically fashioned to work with your unique body chemistry; new materials for harvesting light (for example, roll-out solar panels) that are as efficient as the leaves of plants in capturing the sun’s energy; biodegradable fibres that are as strong and light as spider silk and could be used, say, in plastic bags that never tear; and the ability to store and replicate vast amounts of information (with the same incredible precision as in DNA).
Looking into the future, it is certain that chemistry will continue to be a critical tool in helping us address the problems and challenges faced by humanity.
So the next time you have a sip of water, imagine the possibilities and imagine the power of the molecule. Happy IYC!

Dr. Peter Kusalik is the head of the Department of Chemistry at the University of Calgary. (Photo by Riley Brandt)
