Rate of reaction
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Biology Practical Investigation to find the lowest concentration of Copper Sulphate solution that will denature egg albumen.
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Introduction
Biology Practical Investigation to find the lowest concentration of Copper Sulphate solution that will denature egg albumen Introduction Proteins are organic compounds of large molecular mass. They are not truly soluble in water; instead they form colloidal suspensions. Proteins are made up of amino acids.. There are three main types of bonding. The first is a disulphide bond. This occurs between cysteine molecules in the same amino acid chain (intrachain) or between molecules in different chains (interchain). This is the strongest and last bond to break. The second bond is an ionic bond. At a suitable pH, an interaction may occur between ionised amino and carboxylic groups. This forms an ionic bond. These ionic bonds are weak and can be broken in an aqueous solution by changing the pH of the medium surrounding the polypeptide. ...read more.
Middle
The arrangement of these bonds is the quaternary structure. When protein is denatured the specific shape formed by the four types of structures is broken down. Denaturation is a physical change in the shape of the protein molecule. This is due to the bonds, which normally hold the proteins specific three dimensional shape, being broken Aim of the Experiment To discover the lowest concentration of copper sulphate solution that will denature egg albumen. Prediction The copper sulphate ions will break down the tertiary structure causing the protein to denature. This will cause the egg albumen to turn white and opaque. The higher the concentration of the copper sulphate the faster and more opaque the albumen will turn, this is due to the increase in number of copper ions present in the solution. Apparatus 5 Test tubes Test tube holder Egg Albumen from a fresh egg 0.1Molar Copper Sulphate solution 5 Petri dishes Marker Pen 5ml Syringe ...read more.
Conclusion
This contains nothing other than pure water and no reaction will occur. This is called the control and all the results can be compared to it to determine whether a reaction has occurred. The fixed variables of this investigation are volumes of egg albumen used and the volume of copper sulphate solution. The independent variable is the concentration of copper sulphate. The dependant variable is whether the egg albumen has denatured or not. To ensure fair testing throughout the investigation the egg albumen used was from the same egg. The same volumes were used and measured using a syringe rather than a measuring cylinder, to ensure accuracy. The results obtained are qualitative, as there is nothing that can easily be measured. One way of obtaining quantitative results is to centrifuge the solutions after denaturation has occurred and this will show how much of the albumen has been denatured. Results Table Concentration of Copper Sulphate Solution Observations 0.01M 0.008M 0.006M 0.004M 0.002M 0. ...read more.
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Here's what a teacher thought of this essay
5 star(s)
*****
An excellent description of the structure of proteins.
The report is good thus far, consider how you could make the experiment more reliable (repeats) and how you can ensure that the results are accurate by exploring more variables that need to be controlled.
Also - you stated copper sulphate is an irritant if it makes contact with the
eyes, ensure you include goggles in the equipment list and safety precautions.
Marked by teacher Jon Borrell 08/01/2013
