<prompt> Enantiomers are isomers that differ in structure at which carbon :Last CarbonFirst CarbonPenultimate CarbonCarbonyl Carbon  <response>: Enantiomers have different -H and -OH orientation around the penultimate carbon 2nd last carbonReference carbon. E.g-. D-and L-Glyceraldehyde. Also known as Mirror images of each other. 