Discovering Factors affecting Protein Denaturation
To examine three different ways of denaturing proteins.
HypothesisIt was predicted that the physical characteristics of the egg white solution at room temperature would appear clear and normal like a raw egg white. This is because nothing would be done to the egg white. It was also predicted that when the egg white solution gets heated, the protein would denature if the temperature exceeds 65 °C. The protein would solidify, turn opaque, and turn white in colour. This would happen because the heat at a certain temperature will cause the amino acids in the protein to unravel, thus the protein would lose its structure, and this would reveal a colour change. It was also predicted that when acid is poured into the egg white solution, the proteins would denature and turn into a white colour. This would be because it would result in a further straightening effect on the protein chain. It was also predicted that when silver nitrate is poured into the egg white solution, it would result in some sort of precipitate since silver is always precipitating out. Also, since salts are ionic compounds, they disrupt salt bridges in proteins, and so this can also be a factor.
It was hypothesized that egg whites will not regain their original characteristics when removed from the heat or acid because if the protein bonds get disrupted, then the protein is no longer viable and cannot perform its function when it is partially or fully uncoiled.
ObservationsTable 1: Chart illustrating the pH and appearance of the egg white solution in test tube A at room temperature (25 °C).
Test TubeTemperaturePHAppearanceA25 °C8 - BasicClear solution with foam at the top. Contained tiny white particles floating in the egg white.
Table 2: Chart illustrating the pH and appearance of the egg white solution in test tube B when heated in boiling water for ten minutes.
Test TubeAppearanceBOpaque solution. Cloudy, foamy at the top. Had a creamy colour.
Table 3: Chart illustrating the pH and appearance
HypothesisIt was predicted that the physical characteristics of the egg white solution at room temperature would appear clear and normal like a raw egg white. This is because nothing would be done to the egg white. It was also predicted that when the egg white solution gets heated, the protein would denature if the temperature exceeds 65 °C. The protein would solidify, turn opaque, and turn white in colour. This would happen because the heat at a certain temperature will cause the amino acids in the protein to unravel, thus the protein would lose its structure, and this would reveal a colour change. It was also predicted that when acid is poured into the egg white solution, the proteins would denature and turn into a white colour. This would be because it would result in a further straightening effect on the protein chain. It was also predicted that when silver nitrate is poured into the egg white solution, it would result in some sort of precipitate since silver is always precipitating out. Also, since salts are ionic compounds, they disrupt salt bridges in proteins, and so this can also be a factor.
It was hypothesized that egg whites will not regain their original characteristics when removed from the heat or acid because if the protein bonds get disrupted, then the protein is no longer viable and cannot perform its function when it is partially or fully uncoiled.
ObservationsTable 1: Chart illustrating the pH and appearance of the egg white solution in test tube A at room temperature (25 °C).
Test TubeTemperaturePHAppearanceA25 °C8 - BasicClear solution with foam at the top. Contained tiny white particles floating in the egg white.
Table 2: Chart illustrating the pH and appearance of the egg white solution in test tube B when heated in boiling water for ten minutes.
Test TubeAppearanceBOpaque solution. Cloudy, foamy at the top. Had a creamy colour.
Table 3: Chart illustrating the pH and appearance
Bibliography: 1) http://www.elmhurst.edu/~chm/vchembook/568denaturation.html2)http://www.sumanasinc.com/webcontent/animations/content/proteinstructure.html