BiochemistryEssay Preview: BiochemistryReport this essayExperiment 3Materials:0.1 M phosphate buffer (pH 6.0, 7.0, 8.0), 0.2 M NaOH, 0.1 M tris buffer, Casein solution (0.6% casein in 0.1 M sodium acetate), distilled water, 0.1M acetic acidMethods:Verification of the Henderson-Hasselbalch equation:[pic 1]The tris (hydroxymethyl) aminomethane buffer system:[pic 2]Effect of temperature on buffering capacity:[pic 3]Effect of dilution on buffering capacity:Table 1: Dilution factor of phosphate buffer (pH7.0) and tris buffer (pH8.0)BufferDilution factorVolume of buffer (mL)Volume of ditilled water (mL)Phosphate buffer (pH 7.0)1/102.018.01/500.419.61/1000.219.8Tris buffer (pH 8.0)1/102.018.01/500.419.61/1000.219.8[pic 4]Isoelectric precipitation of casein:Table 2. Volume of casein solution, distilled water and acetic acid in 7 test tubes.Tube1234567Casein (mL)1.01.01.01.01.01.01.0Distilled water (mL)8.98.88.58.07.05.000.1 M acetic acid (mL)0.10.20.51.02.04.09.0[pic 5]Results:Table 3. pH determination of 0.1 M phosphate buffers at pH 6.0, 7.0 and 8.0.0.1 M phosphate bufferInitial pHFinal pHΔpHpH 6.06.246.560.32pH 7.07.237.460.23pH 8.08.1510.342.19
Table 4. pH determination of 0.1 M tris buffer at pH 8.0.0.1 M tris bufferInitial pHFinal pHΔpHpH 8.08.4210.201.78Table 5. pH determination of phosphate buffer at pH 7.0 and tris buffer at pH 8.0 at different temperatures. Buffer Temperature (°C)Initial pHFinal pHΔpHPhosphate buffer (pH 7.0)Ice7.47.430.03277.237.460.23507.257.400.15707.267.450.19Tris buffer (pH 8.0)Ice8.258.280.03278.4210.201.78507.557.930.38707.187.910.73Table 6. pH determination of different dilution factor of phosphate buffer at pH 7.0 and tris buffer at pH 8.0.Buffer Dilution factorInitial pHFinal pHΔpHPhosphate buffer (pH 7.0)1/107.2111.554.341/507.7211.824.101/1008.2911.833.54Tris buffer (pH 8.0)1/108.4611.483.021/508.9411.953.011/1008.4111.883.47Table 9: pH values and amount of precipitation of casein solution with different contentsTube1234567Experimental pH6.005.005.005.004.003.003.00Expected pH5.705.405.004.704.404.103.75Amount of precipitation-++++++++-Type of precipitationClearCloudyFlakesGranularFlakesCloudyClear
Water. (Click for larger image.)>1.2.2.0.0.8.4.4.
Water. (Click for larger image.)>1.2.2.0.0.15.5.5
Plate 1.2.2.2.6.2.2.3.4.5
1.2.2.2.2.2.3.5
1.2.2.2.2.3.6.4.4
1.2.2.2.2.2.4.2
1.2.2.2.2.5.5
Plate 1.2.2.2.6.5.5.6.2.5.6.8.6.7.5.6.7.2.10Cecil. (Click for larger image.)>1.2.2.4.0.0.10.6.8
1.2.2.4.0.0.8.12.1.2.4.1.2.4.0.0.10.7.8Plate 1.2.2.2.5.0.10.
Plate 1.2.2.5.1.
1.4.4.3.1.5
. 1.4.4.1.6.1.
1.4.4.3.2.5
. 1.4.4.3.3.
1.4.5.1.4.
1.4.5.2.0.0.4.4
3.1.2.5.0.0.
1.4.5.3.0.
1.4.5.4.0.
1.4.5.5.0.
1.4.5.6 1.4.6.0.0.
Plate 1.4.6.1.
1.4.6.1. 1.4.6.2.4.
1.4.6.2.3.
1.4.7.0.0
1.4.7.11.4.7.10
Plate 1.4.8.0.
1.4.8.0. 1.4.8.1.
1.4.8.2.0.
1.4.9.0.0.
1.4.
Water. (Click for larger image.)>1.2.2.0.0.8.4.4.
Water. (Click for larger image.)>1.2.2.0.0.15.5.5
Plate 1.2.2.2.6.2.2.3.4.5
1.2.2.2.2.2.3.5
1.2.2.2.2.3.6.4.4
1.2.2.2.2.2.4.2
1.2.2.2.2.5.5
Plate 1.2.2.2.6.5.5.6.2.5.6.8.6.7.5.6.7.2.10Cecil. (Click for larger image.)>1.2.2.4.0.0.10.6.8
1.2.2.4.0.0.8.12.1.2.4.1.2.4.0.0.10.7.8Plate 1.2.2.2.5.0.10.
Plate 1.2.2.5.1.
1.4.4.3.1.5
. 1.4.4.1.6.1.
1.4.4.3.2.5
. 1.4.4.3.3.
1.4.5.1.4.
1.4.5.2.0.0.4.4
3.1.2.5.0.0.
1.4.5.3.0.
1.4.5.4.0.
1.4.5.5.0.
1.4.5.6 1.4.6.0.0.
Plate 1.4.6.1.
1.4.6.1. 1.4.6.2.4.
1.4.6.2.3.
1.4.7.0.0
1.4.7.11.4.7.10
Plate 1.4.8.0.
1.4.8.0. 1.4.8.1.
1.4.8.2.0.
1.4.9.0.0.
1.4.