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 protein is a food with a neutral taste that is used in dairy alternatives such as cheeses[1] and yogurt.[2] It is extracted from the yellow pea, Pisum sativum, and has a typical legume amino acid profile. The genotype of the pea plants affects properties of the protein. Pea protein contains legumin, which has some similar properties to casein, and pea protein products are promoted as an alternative to whey protein. Some marketing of pea protein is based on consumer concerns around genetic modification of soy plants.