Nobel Prize in Chemistry 2012

The Nobel Prize in Chemistry 2012 was awarded jointly to Robert J. Lefkowitz and Brian K. Kobilka "for studies of G-protein-coupled receptors"

The cells in our bodies need to work together, they need sensors to be able to sense what is going on around them. The sensors on the surface of cells are call receptors.

The G-protein-coupled receptors are a family of receptors for adrenalin (epinephrine), dopamine, serotonin, light flavour and odour. A lot of medications that we take act on these receptors.
While these G-protein-coupled receptors are clearly very important, scientists haven't really known very much about how they work until recently.

In 1970 Lefkowitz  announced the discovery of an active receptor. Using radioactive tracers his research group examined how adrenergic receptors, receptors for adrenalin and noradrenalin, work.
In the 1980's his research team started work on trying to find the gene code for the beta receptor in the hope that this would give them clues about how the receptor works.
Kobilka joins the team and has an idea that it makes it possible to isolate the gene.
The receptor is found to consist of 7 long fatty spiral strings (helices).
A different receptor, the light receptor rhodopsin in the retina of the eye, has also been found to be made up of  7 stringed helices.

The groundbreaking discovery was that these two receptors are related even though they have different functions, that is, there is a family of receptors that look alike and function in a similar, yet different, manner.

In 2011 Kobilka and his research team finally got an image of the receptor at the very moment when it transfers the signal from the hormone on the outside of the cell to the G-protein on the inside of the cell.

Reference:
http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2012/popular-chemistryprize2012.pdf