Noun
a colorless crystalline compound found in unripe fruit (such as apples or tomatoes or cherries) and used mainly to make polyester resins
Source: WordNetThe reason for this large difference is that when one proton is removed from the cis isomer (maleic acid) a strong intramolecular hydrogen bond is formed with the nearby remaining carboxyl group. Source: Internet
The most common way to synthesize uracil is by the condensation of maleic acid with urea in fuming sulfuric acid as seen below also. Source: Internet
The difference between fumaric acid and maleic acid is a classic example. Source: Internet