Sugars and amino acids are capable of being put together either way, but once assembled they are stable in one configuration or the other, and do not change from one to the other. The assembly of these molecules is directed by DNA, RNA, and enzymes (themselves made up of amino acids) in the nucleus of a cell, in such a way that the handedness is explicitly laid out in the gene. Once the gene for the sugar or amino acid has evolved it gets passed on to future generations. Evolution explains the handedness quite nicely if you take the trouble to understand the science.
I've seen more than enough to convince me that this universe was deliberately designed.
Designed for what?
There lives more faith in honest doubt, believe me, than in half the creeds.
