Spreadsheet Assignment #6:   Evaluation of Ligand Binding - Oxygen to Hemoglobin

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Ligand binding, such as the case for oxygen binding to hemoglobin, can be described by the equation:

            Y = [pO₂ⁿ]  /   [(pO₂ⁿ) + (p50ⁿ)], 

where pO₂ is the partial pressure of oxygen in torr, p50 is a constant (usually in the range of 20-30 torr), and n is a cooperatively coefficient (ranging from 1 to 3 under physiological conditions).  Calculate the values of Y across the range of 0 to 100 torr for pO₂, and p50 = 25 torr.  Do this for four values of n: 1, 2, 5, and 10.  Create a single plot with four lines, one for each value of n, with pO₂ on the x-axis and Y on the y-axis.  An example layout is shown below:

(p50=25)	n-Values:	.	.	.
pO2	1	2	5	10
0	0.000	0.000	0.000	0.000
1	0.038	0.002	0.000	0.000
2	0.074	0.006	0.000	0.000
3	0.107	0.014	0.000	0.000
4	0.138	0.025	0.000	0.000
...	...	...	...	...
100	0.800	0.941	0.999	1.000

Excel Programming Tips:

Each line or series of points on a chart is called a “series.” Selecting one line (clicking on a line or set of points on the chart) individually shows the source data on the spreadsheet from which it is derived. After finishing a chart you can right click on it and select source or chart options to modify it. To modify an axis title or the graph title you can simply right click on them. To modify the series labels, you need to right click on the chart and select source data. Clicking the series tab will allow you to modify each series title as well as its X and Y data sets.