Protein Denaturation
Practical 3:
Proteins
Introduction:
‘Protein’ also an important food component, we commonly take in from our diet. In this experiment we have studied a certain property of protein, i.e., protein can be denatured by various factors.
A. Denaturation of egg white
Results:
Egg white sample in water baths | Test tube | temperature | Observations | 1 | 60°C | Took 7minutes and 15 seconds to turn white and form white participate. | 2 | 80°C | Took 2minutes and 20 seconds to turn white and form white participate. | Comparison: test tube at 80°C had more white participate than that of 60°C | Addition of Acetic acid and NaCl | Test tube | Chemical added | Observation: number of drops added | 3 | Acetic acid | 2 Drops : turned opaque | 4 | NaCl | 30 Drops ; small white participate observed | In test tube 5, same amount i.e. 20ml of water was added, and it was observed that it turned slightly opaque. Discussion: First of all, major food component in egg white is protein. The results all observed are due to denaturation of protein. Protein can be denatured at high temperature and pH. In test tube 1 and 2, which were placed in water bath, denaturation took place due to high temperature, thus giving a visible change. At high temperature protein molecules start to loss their original structure. When heat is implied, the protein molecule starts to thicken and coagulate and loss their solubility property in water and start to precipitate out. Therefore, in both test tubes white precipitates are observed. However, at 80°C it takes less time to form larger quality of precipitate than at 60°C. As at higher temperature more heat energy is provided to protein molecules and they vibrate more rapidly and thus hit each other rapidly, rate of denaturation is higher. Therefore, at 80°C more participate is observed in less time. In test tube 3, denaturation also takes place due to high pH is acetic acid. The high pH induces bond
Proteins
Introduction:
‘Protein’ also an important food component, we commonly take in from our diet. In this experiment we have studied a certain property of protein, i.e., protein can be denatured by various factors.
A. Denaturation of egg white
Results:
Egg white sample in water baths | Test tube | temperature | Observations | 1 | 60°C | Took 7minutes and 15 seconds to turn white and form white participate. | 2 | 80°C | Took 2minutes and 20 seconds to turn white and form white participate. | Comparison: test tube at 80°C had more white participate than that of 60°C | Addition of Acetic acid and NaCl | Test tube | Chemical added | Observation: number of drops added | 3 | Acetic acid | 2 Drops : turned opaque | 4 | NaCl | 30 Drops ; small white participate observed | In test tube 5, same amount i.e. 20ml of water was added, and it was observed that it turned slightly opaque. Discussion: First of all, major food component in egg white is protein. The results all observed are due to denaturation of protein. Protein can be denatured at high temperature and pH. In test tube 1 and 2, which were placed in water bath, denaturation took place due to high temperature, thus giving a visible change. At high temperature protein molecules start to loss their original structure. When heat is implied, the protein molecule starts to thicken and coagulate and loss their solubility property in water and start to precipitate out. Therefore, in both test tubes white precipitates are observed. However, at 80°C it takes less time to form larger quality of precipitate than at 60°C. As at higher temperature more heat energy is provided to protein molecules and they vibrate more rapidly and thus hit each other rapidly, rate of denaturation is higher. Therefore, at 80°C more participate is observed in less time. In test tube 3, denaturation also takes place due to high pH is acetic acid. The high pH induces bond