Laccase Of Catechol

In order to generate a bicyclic lactone in this experiment, a Diels-Alder adduct was produced. The bicyclic lactone to be generated was cis-1,3,3a,4,5,7a-Hexahydro-5-methyl-3-oxo-4-isobenzofuran-carboxylic Acid and was produced using a Diels-Alder reaction. The product was also analyzed quantitatively using percent yield. To prepare the Diels-Alder adduct 0.40 g of 2,4-hexadien-1-ol was added to a flask, then 5.00 mL of toluene and 0.40 g of maleic anhydride were added to the flask in that order. The mixture was warmed and stirred to induce a reaction. The reaction progress was monitored using a TLC plate with 30:70 hexane used as the mobile phase and silica gel as the stationary phase. The TLC plate revealed a new spot for the crude product, indicating the reaction had begun.

During this experiment, the activity of catechol oxidase and the absorbance of benzoquinone was measured in five solutions with different pH concentration. Five cuvettes provided by the instructor were used during the experiment. The transmittance on the spectrophotometer was zeroed on an empty chamber and it was set at a wavelength of 486 nm. Because the shape of an enzyme changes with different pH concentration and each pH has different chemicals, so five cuvettes containing 0.5 mL of enzyme solution and 4.5 mL of pH 2, pH 6, pH 7, pH 8, pH 11 were used to make five different blank solutions (Scott, S.M. et al 2016). (Each blank was made when needed, not all blanks were made at the same time.)

Lactose is a sugar that can be put into smaller molecules, glucose and galactose. Lactose is when you are not able to digest milk and dairy meaning that the enzyme lactase that breaks down lactose is not functioning properly. ONPG was used as a substitute for lactase because even though it is colorless it helps show enzyme activity by turning yellow. This experiment measured the absorbance ONPG when exposed to lactase within an environment of different salinity’s. The enzyme, lactase, was obtained by crushing a lactaid pill and then was added into four cuvettes. ONPG and salt solution of different concentrations were added and their levels of absorption was measured by a spectrophotometer. The results showed that higher salt concentrations have a lower level of absorption. There were 4 cuvettes and within those cuvettes that solutions within them were being tested and the results showed the more salt solution added with the lactase the lower the absorbance. The less salt solution there was a higher rate of absorbance. The data supported the hypothesis that with increasing NaCl concentration there would be a decrease in enzyme activity.

Wine has several critical components, which create its complex aroma and flavour profile, that oxidise with air. The main oxidisable compounds in wine are phenolics, which include wine pigments. Phenolics or a phenol molecule has a benzene ring structure with a hydroxyl or alcohol functional group (OH) – directly bonded to the benzene ring.

The two experiments investigated measure the activity of the enzyme, catechol oxidase. Specifically, they investigate the effect of decreasing amounts of enzyme on rate of reaction and effect of decreasing amounts of substrate on rate of reaction. Enzymes are proteins with specific structures determined by the sequence of amino acid used to accelerate and regulate biochemical processes; enzyme activity can be measured using the rate at which the reaction catalyzes and can be expressed in concentration of substrate or product. Catechol oxidase, the enzyme used in the experiments, can be found in potatoes and catalyzes the oxidation of catechol to ortho-quinone. This substance turns fruits brown when cut open. The ortho-quinone produced in the experiments was used to determine the reaction rate. The experiments involved enzyme dilutions mixed with water and catechol in experiment II and .026M catechol with water and potassium phosphate in experiment III. Both experiments were measured using a spectrophotometer. My hypothesis for experiment II stated that as the enzyme concentration increased the rate of reaction would also increase at a constant rate, and my hypothesis for experiment III stated that the substrate concentration would increase as the rate of reaction increased at a constant rate. The results concluded that in experiment II the enzyme concentration increased at a constant rate, while the reaction rate increased. The experiment III concluded that the

In order to see the effects of pH and temperature on the enzymatic reaction of catechol oxidase when separated from potato tissue. We used a spectrophotometer to measure how much blue light energy is absorbed by benzoquinone. Benzoquinone is a product of catechol when it has been oxidized by different temperatures and pHs. We hypothesized that the benzoquinone absorbance rate would be faster when the pH added to the cuvettes were greater than the pH of the potato tissue. The pH of the potato tissue was pH 6. Our results show that pH 7 had the faster absorbance rate, slightly slower at pH 4, and slowest at pH

The standard curve was plotted for FeSO4 with concentration range of 0.2-1mM, and there was a strong correlation between FeSO4 concentration and antioxidant capacity (R²= 0.992) and the equation was Y=0.1958X-0.2452. The standard curve displayed a linear trend between 0.2 to 1mM FeSO4. There was strong correlation between pectin concentration and antioxidant activity for all the pectin samples tested (R2=0.9778, 0.9885, 0.9742 and 0.9954), for the native, 100W, 200W and 400W degraded pectin respectively. Sonicated pectin had increased antioxidant activity with 400W treated pectin having 43% relative FRAP activity at 4mg/mL, the same concentration of native pectin had a lower relative FRAP activity 16.4% compared to FeSO4. There was generally increased antioxidant activity with increasing sonication power applied. The results are consistent with the previous observation by Pokora et al., [66], who reported that enzymatic hydrolysis of egg yolk protein and white protein improved their radical scavenging (DPPH) capacity, ferric reducing power, and chelating of iron activity. Native pectin is a complex molecule with complex side group structure, and during sonolysis the large molecule is depolymerized yielding low degree of polymerization pectin , thus exposing prior hidden functional groups and creating functional groups at the scission sites, e.g. carbonyl groups. The reducing agents mostly act as hydrogen/electron atom donors thus

The data in experiment one showed the darkest color in the tube containing the substrate catechol, which was scaled at a 10, and showed no change in any of the other tubes containing the other substrate, which were scaled at 0, showing that the enzyme only reacted with the catechol substrate. This supported the hypothesis that the enzyme would be specific to only one type of substrate, in this case the substrate was catechol, this is known as enzyme specificity. The active site of the catechol oxidase enzyme has as structure that is able to remove the hydrogen of the catechol to create benzoquinone. This is because the oxygen atoms in the catechol oxidase are electronegative enough to pull the hydrogen atoms away from the oxygen atoms present in the catechol.

Enzymes are types of proteins that work as a substance to help speed up a chemical reaction (Madar & Windelspecht, 104). There are three factors that help enzyme activity increase in speed. The three factors that speed up the activity of enzymes are concentration, an increase in temperature, and a preferred pH environment. Whether or not the reaction continues to move forward is not up to the enzyme, instead the reaction is dependent on a reaction’s free energy. These enzymatic reactions have reactants referred to as substrates. Enzymes do much more than create substrates; enzymes actually work with the substrate in a reaction (Madar &Windelspecht, 106). For reactions in a cell it is

The Effect of Different Concentrations of the Enzyme Catechol Oxidase on the Rate of Benzoquinone Production When Mixed with Pure Catechol

In this study, the effects of temperature and pH were measured on the catalytic ability of the enzyme catechol oxidase (also known as tyrosinase, diphenol oxidase, or polyphenal oxidase). Enzymes are defined as catalysts in biological systems that lower that energy of activation or Ea of a reaction. When a substrate bonds to a the active site of an enzyme, this forms an enzyme-substrate complex. An enzyme substrate complex consists of one or more substrates bonded to the enzymes active site, which changes shape slightly when bonded to, so as to appropriately fit the substrate(s). This slight change in enzyme shape is called induced fit.

Polyphenol oxidase catalyzes the oxidation of phenolic compounds into dark pigments (Sukhonthara et al., 2016) Inhibitors that could stop the polyphenol oxidase from catalyzing could stop the browning from occurring. Catechol oxidase is an enzyme that is found in most fruits and vegetables. It is known to enable the browning of cut fruits or vegetables by catalyzing a reaction between catechol and oxygen. The result of this reaction happening would be polyphenol, the browning that occurs when fruits or vegetables are exposed to oxygen. In this experiment, we are measuring different compounds that inhibit catechol oxidase from catalyzing benzoquinones.

“Enzymes are proteins that have catalytic functions” [1], “that speed up or slow down reactions”[2], “indispensable to maintenance and activity of life”[1]. They are each very specific, and will only work when a particular substrate fits in their active site. An active site is “a region on the surface of an enzyme where the substrate binds, and where the reaction occurs”[2].

The carbon-carbon double bond of alkenes represents a site that has a high electron intensity. This site is susceptible to oxidation. Depending on the conditions or reagents used to initiate the oxidation of alkenes, various products can be obtained. With relative mild oxidation, it is only the pi bond of an alkene that is cleaved resulting in the production of 1,2-diols or epoxides. However, when there is more vigorous

The metabolic pathway of L. lactis can function through aerobic and anaerobic reactions. It consists of 621 reactions and 509 metabolites and requires minimally glucose, arginine, methionine, glutamate and valine for growth. The main metabolism of L. lactis is through the anaerobic pathway, fermentation, which produces lactic acid from the available carbohydrates and is used for industrial food production. The carbon sources that L. lactis draws from include fructose, galactose, glucosamine, glucose, lactose, maltose, mannitol, mannose, ribose, sucrose and trehalose. However, the growth rate of the cell with the intake of each carbon source is different. Growth rate on glucose, mannose, galactose, sucrose, lactose and glucosamine are the same,