How do L-amino acids differ from D-amino acids?

L-amino acids and D-amino acids are chiral molecules that exist as mirror-image isomers, similar to the relationship between a left and right hand. With the exception of glycine, all amino acids possess an asymmetric $\alpha$-carbon atom, allowing for these two distinct spatial arrangements.12

The primary differences and characteristics include:

• Biological Prevalence: Proteins in living organisms are composed almost exclusively of L-amino acids because the enzymes responsible for protein synthesis have evolved to utilize only this configuration.12
• Occurrence of D-isomers: D-amino acids are not synthesized in the ribosome. However, they are found in specific contexts, such as within the cell walls of bacteria and in certain antibiotics like gramicidin and bacitracin.12
• Optical Activity: These isomers exhibit optical rotation, meaning they rotate the plane of polarized light. While the d (dextrorotatory) and l (levorotatory) designations refer to the direction of this rotation, the L- and D- prefixes specifically denote the geometric configuration of the molecule.2