Following is a simple calculator to compute the net ATPs and Oxygen consumed and the net P:O ratio assumed, during the breakdown of an even chain fatty acid by ß-oxidation. Just enter the number of carbon atoms corresponding to the even chain fatty acid and the number of double bonds in the same.
Note: The cursor won't blink, just click the cell/s where you wish to input the values (for 'n' and 'x'). Further, the equation and the values for an odd chain fatty acid vary (in the constants) and merit a separate discussion.
When you compute the values for all fatty acids in a table; as a function of chain length and double bonds and plot them in a graph, you will see a clear asymptotic pattern.
A note on the value of P:O ratios for NADH2 and FADH2 - The current estimates assume a yield of 3 ATPs and 2 ATPs respectively. When revised estimates (Hinkle and Yu) of 2.5 and 1.5 and taken into account, the only change in the equation (for the fatty acid P:O) is that of the constants. Otherwise, one would observe the same asymptotic patterns.
Efficiencies of fatty acid breakdown for energy can be represented by equation that resembles a rectangular hyperbola. This equation possibly governs the selective mobilization and distribution of the different types of fatty acids in white adipose tissues.
The following document shows the derivation of the equation (for even chain and odd chain fatty acids) and the general equation to show that it is a rectangular hyperbola ...
