AIM: Is to determine the kinetics of a pseudo first order reaction. THEORY The pseudo first order reaction is the reaction that is a second order but can be approximated to be first order under a special circumstances. In the experiment the kinetics of the oxidation of GSH by Cr (VI) is studied at neutral pH, which result in formation of glutathionyl disulfide. The glutathione is a tripeptide with a gamma peptide bond between carboxyl group of the glutamate side chain and the amine group of cysteine. Due to its chemical structure, glutathione may protect against oxidation. The overall reaction mechanism for the reaction: Figure 1: structure of GSH (R.J.Silbey, etal.2004) figure 2: formation of GSSG (R.J.Silbey, …show more content…
The reversible formation of chromium (IV) thioester intermediate: CrO42- + GSH ↔ CrO42- - GSH (Thioester) Thioester + GSH → GSSG The spectrophotometer at the wavelength of 370 used to measure the absorbance of the solution. Oxidation: occur when a reactant loses electrons during the reaction. Reduction: occur when a reactant gains electrons during the reaction. Absorbance: is a measure of the quantity of light absorbed by a sample. Spectrophotometer: is an instrument that measures the amount of photons absorbed after it passes through sample …show more content…
The sample cell was removed and the data acquisition began. 200µl of the Cr (VI) solution was injected with a micropipette into the sample, inverted it several times and placed in a cell compartment fasted. The absorbance values were recorded every 20 seconds for a period of 40 minutes. DISCUSSION During the experiment the kinetic behaviour of the redox reaction between the GSH and Cr(IV) was investigated. The GSSG which is glutathionyl disulfied formed by two GSH units that coupled together through the thiol groups. The Chromium ion in the 6 oxidation reduced to Cr (III) due to the present of oxygen. The GSH and GSSG operate as redox couple, both in intracellular and plasma environments. GSH provides an important defence mechanism against certain toxic compounds that scavenges reactive species such as free radicals and peroxides, and the Cr(VI) interfered these process by causing a depletion of GSH. In the experiment the GSH and H+ behave as a first order in the presence of excess concentration, which means they are pseudo first order reaction. The concentration of chromium ions monitored throughout the
Living organisms undergo chemical reactions with the help of unique proteins known as enzymes. Enzymes significantly assist in these processes by accelerating the rate of reaction in order to maintain life in the organism. Without enzymes, an organism would not be able to survive as long, because its chemical reactions would be too slow to prolong life. The properties and functions of enzymes during chemical reactions can help analyze the activity of the specific enzyme catalase, which can be found in bovine liver and yeast. Our hypothesis regarding enzyme activity is that the aspects of biology and environmental factors contribute to the different enzyme activities between bovine liver and yeast.
Oxidative stress is essentially defined as the imbalance in the equilibrium of antioxidants systems in the human body. Oxidative damage in aerobic organisms can be caused by certain molecules known as reactive oxygen species (ROS). These reactive species are ones that cause oxidative damage in biomolecules. In order to maintain equilibrium of these substances, the human body has various endogenous antioxidants and phase 2 proteins which have evolved to defend against any harmful effects of ROS or any other reactive species. In normal physiological conditions, a balance is maintained between the ROS production and their detoxification by the appropriate antioxidants and phases 2 proteins. (Uttara, Singh, Zamboni & Mahajan, 2009). Oxidative stress can occur due too many pathological conditions, when the balance of prooxidants and antioxidants is disturbed oxidative damage could accumulate in proteins, lipids, carbohydrates and nucleic acids. In severe cases these events can lead to cell death. The process can directly alter the antioxidant systems by either inducing or inhibiting the proteins which take part in these systems. Moreover it can also cause the depletion of storage of antioxidants such as glutathione, vitamin E and many more in cells. (Thomas 2006). Antioxidants are defined as any substance which has the ability to inhibit, reduce or repair the damage as a result of an ROS in a biomolecule. The general three mechanisms that are used by antioxidants include the inhibition of ROS generation, the repair of damage induced by ROS and scavenging for ROS molecules. Since ROS plays a precarious role in both physiology and pathophysiology in the human body, it is vital that the endogenous antioxidants and phase prote...
Chemical kinetics is a branch of chemistry that involves reaction rates and the steps that follow in. It tells you how fast a reaction can happen and the steps it takes to make complete the reaction (2). An application of chemical kinetics in everyday life is the mechanics of popcorn. The rate it pops depends on how much water is in a kernel. The more water it has the quicker the steam heats up and causes a reaction- the popping of the kernel (3). Catalysts, temperature, and concentration can cause variations in kinetics (4).
This is the experiment that will carried out, I will now put this equation into word format: Sodium Hydrochloric Sodium Sulphur [IMAGE]Thiosulphate+ Acid Chloride+ Dioxide + Water + Sulphur The sodium thiosulphate consists of: two atoms of sodium, two atoms of sulphur and two atoms of oxygen. This combined with the hydrochloric acid creates a chemical reaction and the products are 2 molecules of sodium chloride, a molecule of sulphur dioxide, water and sulphur. Rate of reaction: The rate of reaction is the speed or velocity at which a chemical
The aim of this experiment was to investigate the affect of the use of a catalyst and temperature on the rate of reaction while keeping all the other factors that affect the reaction rate constant.
We have no gases and solids involved, therefore it is easy to deal with solutions. Similarly, the use of a catalyst complicates things, and if used incorrectly could alter the outcome of the experiment. The theory behind this experiment is that increasing the concentration can increase the rate of the reaction by increasing the rate of molecular collisions. GRAPH I will place the reaction mixture on a paper with a black cross drawn on it. When the cross is completely obscured, the reaction will be finished.
Dependent variables: The extent of the reaction (the time taken for magnesium to completely dissolve in HCL). The volume of hydrogen gas produced.
Wang, F., Gao, F., Lan, M., Yuan, H., Huang, Y., & Liu, J. (2009). Oxidative stress
In this experiment three different equations were used and they are the Stoichiometry of Titration Reaction, Converting mL to L, and Calculating the Molarity of NaOH and HCl (Lab Guide pg. 142 and 143).
Support your body’s natural defenses and reach your peak mental and physical level with Cellgevity. Cellgevity, the premiere nutritional formula from Max International, supports the production and efficient use of glutathione in the body. Glutathione is used by the body to eliminate toxic materials and can even repair damaged cells. It improves the immune system and increased strength and endurance. Containing a blend of D-ribose and L-cysteine known as RiboCeine, Cellgevity works to detoxify the body, combating free radicals, heavy metals and other toxins that damage your body. D-ribose is a sugar produced by the body and used as
To better understand L-Glutathione, you should consider that it is developed in the liver utilising 3 amino acids, it protects the human body from toxins, it can be sourced from certain vegetables and fruit, and its production could be triggered if you take certain supplements.
This is a nearby second to glutathione in criticalness in our cells and is included in vitality generation, glucose control, cerebrum wellbeing and detoxification. The body typically makes it, yet given all the hassles we are under, we regularly become
Oxidative Therapy: It must be understood that oxygen therapy can be administered in many forms, yet the basis behind the treatments are essentially the same. For instance, hydrogen peroxi...
... dichromate, under acidic conditions. A known excess amount of this oxidant is added to the sample and once the process is completed, the COD concentration value is calculated by measuring the remaining amount of oxidant in the solution. This process is usually done through titration by use of an indicator solution. It is measured in milligrams per liter, and indicates the mass of oxygen consumed per liter of solution.
The first experiments investigate the order of reaction with respect to the reactants; hydrogen peroxide, potassium iodide and sulphuric acid by varying the concentrations and plotting them against 1/time. An initial rate technique is used in this experiment so ‘the rate of reaction is inversely proportional to time.’ To find the order of reaction in respect to the reactants, 1/time is plotted against the concentration of Hydrogen Peroxide using the equation: