Seems botlike to you?Polyphenol oxidase (PPO or monophenol monooxygenase or Polyphenol oxidase I, chloroplastic) is a tetramer that contains four atoms of copper per molecule, and binding sites for two aromatic compounds and oxygen.[1] The enzyme catalyses the o-hydroxylation of monophenols (phenol molecules in which the benzene ring contains a single hydroxyl substituent) to o-diphenols (phenol molecules containing two hydroxyl substituents). They can also further catalyse the oxidation of o-diphenols to produce o-quinones. It is the rapid polymerization of o-quinones to produce black, brown or red pigments (polyphenols) that is the cause of fruit browning. The amino acid tyrosine contains a single phenolic ring that may be oxidised by the action of PPOs to form o-quinone. Hence, PPOs may also be referred to as tyrosinases.
Arctic Apples are a suite of trademarked apples that contain a nonbrowning trait. Specifically, gene silencing is used to turn down the expression of polyphenol oxidase (PPO), thus preventing the fruit from browning. They are therefore genetically modified food.[2]
That's because it probably is. http://www.wsj.com/articles/for-this-au ... 1405305001
(Did some research, the particular quote I used was uploaded by K.murphy, edited by a couple bots and a couple people. More importantly, I'm having serious deja vu from this right now...)