Carboxyl groups have an electronegative oxygen atom double bonded to a carbon atom. This carbon-oxygen bond is very polar and the fact that its a double bond increases the polarity of the bond.
PEA agar, also referred to as Phenylethyl Alcohol Agar is a medium  used by microbiologists to grow microorganisms. The ingredient that  supplies nitrogen is casein. Making the world better, one answer at a time.
Pea sprouts contain a high concentration of diamines oxidase (the enzyme that degrades extra-cellular histamine) during the cotyledon phase. All the fabaceae family contain DAO, but it is particular high in, pea (pisum sativum), lentil (lens culinaris), and chickpea (cicer arietinum) seedlings.