Final answer:
The 3-letter abbreviation for Glycine is GLY, used in the context of describing protein or peptide sequences.
Step-by-step explanation:
The 3-letter abbreviation for the amino acid Glycine is GLY. This is the standard format used when describing the primary structure of proteins or peptides, with the sequence listed from N-terminus to C-terminus. For instance, a tripeptide sequence like Glycine-Histidine-Lysine would be abbreviated as Gly-His-Lys.
However, amino acids can be further abbreviated into one-letter codes when dealing with longer protein sequences. For example, Glycine in one letter code is represented as 'G'.
It is crucial to note that the sequence of amino acids is significant because rearranging the sequence can lead to different compounds with different properties. The primary structure of proteins is defined by the precise sequence of amino acids linked by peptide bonds, which determine the protein's unique characteristics and functions.