New clue to life's chemical origins

Posted by Kate Taylor

British chemists at the University of York have moved closer towards establishing the origin of the carbohydrates that form the building blocks of life.

A University of York team says it's re-created a process which could have occurred in the prebiotic world, showing how simple sugars –threose and erythrose — developed.

All biological molecules have an ability to exist as left-handed forms or right-handed forms. But while all sugars in biology are made up of the right-handed form of molecules, all the amino acids that make up the peptides and proteins consist of the left-handed form.

However, the researchers found that using simple left-handed amino acids to catalyse the formation of sugars resulted in the production of predominately right-handed form of sugars - possibly explaining how carbohydrates originated and why the right-handed form dominates in nature.

"There are a lot of fundamental questions about the origins of life and many people think they are questions about biology. But for life to have evolved, you have to have a moment when non-living things become living - everything up to that point is chemistry," says Dr Paul Clarke.

"We are trying to understand the chemical origins of life. One of the interesting questions is where carbohydrates come from because they are the building blocks of DNA and RNA. What we have achieved is the first step on that pathway to show how simple sugars – threose and erythrose — originated. We generated these sugars from a very simple set of materials that most scientists believe were around at the time that life began."