Question

I have questions 1-5. I just need help with number 6. Thank you!

Assume that the concentration of the glucose standard sample is 1.200 mg/ml. Use the following results to perform your calculations: 1. Calculate the concentration of glucose in tubes 1 through 5 (in mu g/ml). 2. Make graphs of A_ vs. concentration and A_ vs. amount (in mu g). It is suggested that you use the program module Excel in Microsoft Office. Instructions are provided in Statistical Calculations Using the Excel Spreadsheet Program in the Analysis of Results section. A more detailed account is provided in the How to make Graphs in Excel section of the chapter Biochemical Tools 3. Analyzing Your Data. 3. Using Excel, place a best lit line (a trendline) through the field of points on the graph that best reflects the average relationship of absorbance to concentration. Now draw the best handdrawn line you can to fit the data. Compare the line with the data. Is the assumption of linearity reasonable? (The absorbance often falls below the linear trend as the [glucose] becomes small.) 4. When you set up the assays, you also prepare tubes numbered 6, 7, and 8. All three contained the same contents using a glucose solution of unknown concentration in place of the standard glucose solution. The unknown glucose solution volume was 0.60 ml: the samples contained 2.40 ml of water. They were incubated along with tubes 1 through 5. The A_ values determined for these tubes were 0.322, 0.298, and 0.288, respectively. These values are indicated in Table A.1-1. Using your graph from question 3, calculate the concentration of glucose in each tube 6, 7, and 8. 5. (a) Calculate the average concentration of tubes 6, 7, and 8. (b) Calculate the standard deviation in that average. 6. Calculate the original concentration of the glucose unknown solution

Answer 1

The readings 6,7 and 8 show the absorbance readings for the unknown glucose solution.

Take the average of these readings, which gives: (0.322 + 0.298 + 0.288)/3 = 0.303

Put this value of absorbance in the beer's law equation that you have developed from the calibration plot.

This will give the required value of the unknown conc.

Hope this helps !