• Question: hey im sophie what do you mean by ussing light from a powerful laser to see if I can explain why the building blocks of life are the way that they are?

    Asked by sophieloren to Steve on 23 Jun 2011.
    • Photo: Steven Daly

      Steven Daly answered on 23 Jun 2011:

      Hey Sophie,
      Great question, I shall do my best to explain.

      There are lots of different molecules that make up our bodies, but one of the most important are proteins. These do most the the chemical reactions in the body, including making copies of your DNA. The building blocks of proteins are called amino acids, and these come in two forms which are called the R-form and the S-form. If you made some amino acid in a reaction in your class, it would be made from 50% R and 50% S form, but in the body there is only the S-form. The R-form is quite often toxic.

      The reason for this is not really well understood, but it could be key to understanding how life formed. If we can find something in nature that makes one type of the amino acid but not the other. What I look at with the lasers is one possible thing that could do this. It has to do with how light will interact differently with the R and S forms of the amino acid, which can lead to them being separated in space. Then if one of the forms can find it way to earth – on a comet say – then this could lead to the conditions needed to make life.

      I hope that was clear!