Why do all organic molecules have the same chirality or handedness?

This is a sobering realization when you open a bag of white sugar and see all the beautiful crystals; not only is this material chemically pure (i.e., it matches the formula of sucrose, whatever this is), it is also optically pure (AND IT'S CHEAP TOO!). Sucrose has a specific handedness, and its optical isomer (not available from sugar cane or beet) would not be metabolized because the enzymes that catalyze sugar metabolism are handed as well, so they can only work on one optical isomer.

Naturally, sucrose comes from a biological source, and proteins, which come from a biological source as well, also have a tendency to be one handed.

It must be an extremely taxing task for both organic and inorganic chemists to isolate materials of both optical antipodes in the laboratory.

All organic molecules have the same chirality because biological processes predominantly favor one enantiomer over the other due to the specific arrangement of functional groups in enzymes. This preference leads to the uniform chirality observed in biological molecules.