Carbohydrates: Glucose and Taste Threshold
Practical 1 : Carbohydrates
Introduction : Carbohydrates are important to human life , this practical is to investigate physical , functional and sensual properties of different carbohydrates , including monosaccharides and disaccharides .
Experiment 1
Title : Relative Solubility of Carbohydrates , Glucose , Galactose and Lactose .
Objective : To determine the relative solubility of glucose , galactose and lactose by measuring their saturation point at the same constant temperature.
Principle : With 10g distilled water contained in a beaker , then add small quantities of the carbohydrate being test at a time with constant stirring until no more can dissolve , saturation point is represented at r.t.p.. Test the carbohydrates , glucose , galactose and lactose , relative solubility of them can be compared.
Precaution : 1) When using magnetic stirrer to stir the mixture , or stirring the solution manually , the speed should not be too fast to prevent splash out of solution and give inaccurate result . 2 ) The temperature of which the experiment performed should remain constant , otherwise solubility of the sugars would be affected and give an inaccurate result.
Results :
sugars Initial reading ( g ) After addition of water ( g ) Final reading ( g ) Sugar added ( g )
Galatose 36.55
43.87
45.52
1.65
Lactose 37.40
45.47
46.33
0.86
Glucose 36.56
44.01
48.97
4.96
sugars water added ( ml ) Saturation point ( mg / ml )
Galatose 43.87-36.55 = 7.32
( 1.65 x 1000 ) / 7.32 = 225
Lactose 45.47-37.40 = 8.07 ( 0.86 x 1000 ) / 8.07 = 107
Glucose 44.01-36.56 = 7.45
( 4.96 x 1000 ) / 7.45 = 666
Conclusion : Relative solubility of glucose is the highest , which is 666mg/ml , and lactose is the lowest , which is 107mg/ml.
Discussion : Comparing saturation points of the three sugars and consider how this relates to the use of them in humans .
The saturation
Introduction : Carbohydrates are important to human life , this practical is to investigate physical , functional and sensual properties of different carbohydrates , including monosaccharides and disaccharides .
Experiment 1
Title : Relative Solubility of Carbohydrates , Glucose , Galactose and Lactose .
Objective : To determine the relative solubility of glucose , galactose and lactose by measuring their saturation point at the same constant temperature.
Principle : With 10g distilled water contained in a beaker , then add small quantities of the carbohydrate being test at a time with constant stirring until no more can dissolve , saturation point is represented at r.t.p.. Test the carbohydrates , glucose , galactose and lactose , relative solubility of them can be compared.
Precaution : 1) When using magnetic stirrer to stir the mixture , or stirring the solution manually , the speed should not be too fast to prevent splash out of solution and give inaccurate result . 2 ) The temperature of which the experiment performed should remain constant , otherwise solubility of the sugars would be affected and give an inaccurate result.
Results :
sugars Initial reading ( g ) After addition of water ( g ) Final reading ( g ) Sugar added ( g )
Galatose 36.55
43.87
45.52
1.65
Lactose 37.40
45.47
46.33
0.86
Glucose 36.56
44.01
48.97
4.96
sugars water added ( ml ) Saturation point ( mg / ml )
Galatose 43.87-36.55 = 7.32
( 1.65 x 1000 ) / 7.32 = 225
Lactose 45.47-37.40 = 8.07 ( 0.86 x 1000 ) / 8.07 = 107
Glucose 44.01-36.56 = 7.45
( 4.96 x 1000 ) / 7.45 = 666
Conclusion : Relative solubility of glucose is the highest , which is 666mg/ml , and lactose is the lowest , which is 107mg/ml.
Discussion : Comparing saturation points of the three sugars and consider how this relates to the use of them in humans .
The saturation