So this is chiral, and that means it contains a mirror image. Now, inside the proteins of our body, this is the only nantomer of isolucine that we actually find when this H atom is coming out of the board, as shown in the following diagram. Now, let's move on to methionine. So what exactly is the difference between these here and methionine? Well, unlike these, the methionine side chain contains a sulfur atom. Now, what's the electronegativity of sulfur as compared to the carbon?