The fat of a common mussel-secretes a sticky glue that can be used to make heart implants. The unique chemical compound present in the glue is: (1) Amino phenyl alanine (2) Hydroxy phenyl alanine (3) Phenyl alanine (4) Dihydroxy phenyl alanine
(4) Dihydroxy phenyl alanine Explanation: The foot of the common mussel (Mytilus edulis) produces a sticky glue due to a unique compound called mussel adhesive protein, which contains a high concentration of an amino acid, DOPA (dihydroxyphenylalanine), which can cling to wet surfaces with extraordinary strength. Besides heart implants, the compound could be used as a tooth coating to prevent dental plaque, which is caused by bacterial infection.