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.
INGREDIENTS IN SHAKEOLOGY. Pea Protein: Extract of a legume. This protein source is low in the amino acids cysteine and methionine. Because of these lacking amino acids, it needs to be mixed alongside other forms of protein, otherwise it would not satisfy as being a quality source of protein.