Hello Everyone,
I am trying to make a double reciprocal plot from my enzyme data. I am not sure how to go from a basic scatter plot chart to a double reciprocal plot.
I got my macbook in 2014 and the software is: OS X 10.9.5 (13F1603)
Thank you very much in advance.
Kind regards,
J
MacBook Pro
Hi j,
Weber State University, in Ogden, Utah, has a set of instruction on doing a Lineweaver Burk plot in MS Excel, that you can find here. The formulas for converting the data pairs are simple reciprocals, and the chart itself is a scatter plot with a 'best fit' linear trend line added. Creating a similar chart in Numbers should be fairly straightforward using the Excel instructions.
Regards,
Barry
Hi Barry,
I checked the site. It didn't show how to make a correct graph using numbers. Also their example was different from the one I need.
Ok. The Ogden professor's interpretation of "Lineweaver Burk plot" would appear to be different from what you are asking for. Can you provide a more detailed description of a Lineweaver Burk plot, and of the data that is plotted compared with the data that has been measured, and is recorded on your data table. The green anb blue trend lines on your chart appear to be related to the data in the (unlabelled) columns E, F and G of your table. How was this data derived? What labels should be on each column?
Regards,
Barry
This picture is what I'm trying to do with my chart.
http://pubs.acs.org/cen/images/8124/8124scit1.ce.gif
The chart shows the initial velocity of the substrates with and without inhibition. The three unlabelled columns are the reciprocal values of the input data in order.
Regards,
J
So something like this, then?
The data from your table is in rows 4-7 of columns A, B and C.
This is converted to the reciprocal values in rows 4-7 of columns E, F and G respectively, header labels are added in row 1 (a header row), and cells E4-G7 are selected and a scatte chart created. When trend lines and the trend line equations are added, it resembles the one in your initial post.
Numbers will not plot trend lines extending beyond the supplied data, so to extend the two lines to meet the x axis, it is necessary to determine the pont where they would cross the x axis by solving the two expressions for y=0. This is done using the constant values in the equations for each slope, shown at top left of the chart, in formulas in E2 and E3.
E2: =(0-16.726)/6.9768
E3: =(0-16.653)/2.4468
Zeroes are added manually in G2 and F3 to specify the Y value where each slope meets the x axis, then the chart is selected again, and the selection rectangle enclosing cells E4-G7 is slid up two rows, then extended down two rows to include cells E2 - G7.
Touch-ups: The chart was stretched horizontally, major ticks added to the x axis, and a vertical line inserted and placed at the 0 point on the x as\xis to serve as the y axis.
Regards,
Barry
Lineweaver Burk Plot (Double Reciprocal Plot)
