Question

Sucrose Levels

Data:

Tube #	1	2	3	4	5	6	7	8	9	`0	11
Water (mL)	1.0	0.75	0.5	0.25
Glucose Std. (mL)		0.25	0.5	0.75	1.0
Sucrose Std. (mL)						1.0	1.0
CONC. Extract (mL)								1.0	1.0
Diluted Extract (mL)										1.0	1.0
Buffer (mL)	1.0	1.0	1.0	1.0	1.0	1.0		1.0		1.0

TUBE VS ABSORBANCES:

1	blank
2	.071
3	.535
4	.551
5	.042
6	0
7	.306
8	.056
9	1.999
10	.025
11	.35

A) Create a standard curve of A540 vs. mg glucose (tube 2-5) and determine the amount of reducing sugar in tubes 6-11.

B) Calculate the concentration of reducing sugar in the enzyme-treated concentrated extract or in the untreated concentrated extract. The absorbance reading of tubes 8 and 9 may be off the standard curve; if so, use the diluted samples (tubes 10 and 11) to make your calculation. The sucrose concentration in the untreated extract is calculated from the difference between the treated and untreated values. Remember to take account of the molecular weights of sucrose (342.3) and glucose (180.2).

C) (If allowed) Calculate the percentage of sucrose and the percentage of reducing sugar (glucose-equivalent) in the dry cereal that you analyzed.

Answer 1