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Explain what happens to catechol oxidase when the pH is on either side of the optimum?
Wiki User
∙ 14y ago
When the pH is not at its optimum, then the differing pHs will disrupt the bonding between the R groups of the amino acid. This will change its shape, altering the shape of the activation site. Within an acceptable pH range, the enzyme will continue to function but since the shape of the activation site has been slightly altered, the reactions won't be able to proceed as quickly as they could at the optimum pH. The further away from the optimum pH, the more the shape of the activation site will change. Eventually, the substrate won't fit into the activation site and the reaction will stop.
Wiki User
∙ 14y ago
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What pH level does catechol oxidase work best a?
pH 10 and 12
What happens to catechol oxidase when pH is on either side of the optimum?
When the pH is not at its optimum, then the differing pHs will disrupt the bonding between the R groups of the amino acid. This will change its shape, altering the shape of the activation site. Within an acceptable pH range, the enzyme will continue to function but since the shape of the activation site has been slightly altered, the reactions won't be able to proceed as quickly as they could at the optimum pH. The further away from the optimum pH, the more the shape of the activation site will change. Eventually, the substrate won't fit into the activation site and the reaction will stop.
Why does lemon juice sprinkled on freshly cut fruit keep the fruit from turning brown?
When plants are cut they release a chemical called catechol and an enzyme called catechol oxidase. The enzyme converts catechol to benzoquinone which is toxic to bacteria. Benzoquinone is intended to prevent microbe invasion. It is this chemical that gives plants a brown color. The citric acid in lemon juice denatures the catechol oxidase, rendering it ineffective. Thus no benzoquinone is produced and plants do not turn brown.
How can you easily distinguish enterics and pseudomonads?
Enterics are oxidase negative while pseudomonads are oxidase positive.
Why are strict aerobes oxidase positive?
Strict aerobes must be oxidase positive because oxidase is an enzyme. It is critical to cellular respiration, specifically the final reduction of oxygen in the electron transport chain.
What enzyme breaksdown catecholamine?
monoamine oxidase and catechol-O-methyltransferase
Does catechol oxidase have a co factor?
Yes, Copper II Chloride
What pH level does catechol oxidase work best a?
pH 10 and 12
Why does lemon juice applied to slices of apples or bananas prevent darkening of the fruit?
beacuse the acidic ph caused by lemon juice prevents the oxidation of catechol by catechol oxidase which results in the absence of the product benzoquinone which is brown in color.
Why does potato extract turn brown when catechol oxidase is added?
It is because the enzyme facilitates a reaction between catechol and oxidase. In the presence of oxygen, the compound catechol is oxidized by the removal of two hydrogen atoms. Catechol is thus converted to benzoquinone, and oxygen is reduced by the addition of two hydrogen atoms to form water. Benzoquinone molecules then link together to form long, branched chains. These chains are the structural backbones fo the read and brown melanoid pigments that cause the darkening. The intensity of the colour depends on the amount of the coloured product formed.
What happened to the structure of catechol oxidase at temperatures above 75C?
it is "denatured" - its structure become very much distorted and thus the protein cannot work anymore
Optimum temperature of polyphenoloxidase?
The optimum temperature for the enzyme polyphenol oxidase (PPO) is 40 degrees Celsius. This is the temperature at which the enzyme is most effective; like many other enzymes the rate of reaction will decrease with temperature, but if the temperature rises much above the optimum level, it will cause the enzymes to denature. Denatured enzymes will stay denatured even if the temperature decreases again. The optimum pH for polyphenol oxidase is 5.
What is the optimum salt concentration for catecholase?
The optimum salt concentration for catecholase is 2%. Absorbance rates in a reaction in which involves the catecholase enzyme peak when the salt concentration is at 2% given other factors remain constant.
What has the author Z L Kruk written?
Z. L. Kruk has written: 'Some effects of inhibiting catechol-o-methyltransferase and monoamine oxidase in the central nervous system of the rat with particular reference to thermoregulatory mechanisms.1972'
What happens to catechol oxidase when pH is on either side of the optimum?
When the pH is not at its optimum, then the differing pHs will disrupt the bonding between the R groups of the amino acid. This will change its shape, altering the shape of the activation site. Within an acceptable pH range, the enzyme will continue to function but since the shape of the activation site has been slightly altered, the reactions won't be able to proceed as quickly as they could at the optimum pH. The further away from the optimum pH, the more the shape of the activation site will change. Eventually, the substrate won't fit into the activation site and the reaction will stop.
How do you keep pears from turning brown?
because of polyphenol oxidase which reacts on pear for sometime.Polyphenol oxidase (PPO) enzymes, also known as polyphenoloxidases, are able to catalyze the transformation of an array of aromatic compounds that have two adjacent phenolic groups on them. This includes a number of polyphenols in plants that act as antioxidants. These copper-containing enzymes oxidize the phenolic groups to reactive oxygen molecules known as quinones, which continue reacting with each other and other cellular factors to form brown spots known as melanin. This browning causes the deterioration of fruits and vegetables, resulting in large economic losses. Examples include the pearEnzymatic browningis not unique to pear. PPO - a mixture of monophenol oxidase and catechol oxidase enzymes - is present in nearly all plant tissues, and can also be found in bacteria, animals, and fungi. In fact, browning by PPO is not always an undesirable reaction; the familiar brown color of tea, coffee and cocoa is developed by PPO enzymatic browning during product processing.Tentoxin has also been used in recent research to eliminate the polyphenol oxidase activity from seedlings of higher plants. Enzymatic browning is not unique to apples. PPO - a mixture of monophenol oxidase and catechol oxidase enzymes - is present in nearly all plant tissues, and can also be found in bacteria, animals, and fungi.
Why does lemon juice sprinkled on freshly cut fruit keep the fruit from turning brown?
When plants are cut they release a chemical called catechol and an enzyme called catechol oxidase. The enzyme converts catechol to benzoquinone which is toxic to bacteria. Benzoquinone is intended to prevent microbe invasion. It is this chemical that gives plants a brown color. The citric acid in lemon juice denatures the catechol oxidase, rendering it ineffective. Thus no benzoquinone is produced and plants do not turn brown.
