Potato Enzymes: Polyphenoloxidase Activity
What is polyphenoloxidase and what is its role in potatoes?
Polyphenoloxidase is an enzyme present in potatoes that plays a key role in their defense mechanism against herbivores.
Why does the activity of polyphenoloxidase increase in peeled potatoes?
Herbivores are organisms that feed on plants. Plants have different mechanisms of defending against herbivores, mostly by synthesizing compounds that give the plants a bitter or unpleasant taste. The synthesis of these molecules is intensified when the plant and its cells suffer physical damage, so, in the case of peeled potatoes, there should be an increase in activity of this protective enzyme.
Polyphenoloxidase Activity in Potatoes
Polyphenoloxidase is an enzyme found in potatoes that is involved in their response to physical damage caused by herbivores. When potatoes are peeled, the cells are disrupted and this triggers an increase in the activity of polyphenoloxidase.
Polyphenoloxidase, also known as PPO, is an enzyme that catalyzes the oxidation of phenols to quinones. In potatoes, this enzyme is part of the defense mechanism against herbivores. When the cells of the potato are damaged, either by herbivores feeding on them or by physical manipulation like peeling, the level of polyphenoloxidase activity increases.
One of the functions of polyphenoloxidase in potatoes is to convert phenolic compounds into quinones, which are toxic to herbivores. When the potatoes are peeled, the disruption of the cells causes an increase in the activity of polyphenoloxidase, leading to a higher production of quinones. This increase in toxic compounds acts as a defense mechanism, deterring herbivores from feeding on the potatoes.
Overall, the increase in polyphenoloxidase activity in peeled potatoes is part of the plant's response to physical damage, enhancing its defense against herbivores. This enzyme is just one of the many components in the potato's defense arsenal, showcasing the intricate ways in which plants protect themselves from predators.