(a) Give the key reaction that illustrates the inhibition of fat oxidation by the preservative BHT. 

(b) The extent to which fat is oxidized in the body can be determined by measuring the amount of pentane exhaled in the breath. Increasing the amount of vitamin E in the diet decreases the amount of pentane exhaled. Examine the processes and identify one that could produce pentane. You will have to do some extrapolating from the specific reactions shown in the section.