Oxidation reactions are one of the primary sources of metabolic energy in living systems. Organic substrates such as sugars and fatty acids are commonly oxidized by oxygen (O, ), a strong oxidant that is readily available in the atmosphere, and thus in biological systems. These bioreactions are catalyzed by enzymes in the presence of cofactors, such as NAD+, that aid in the transfer of electrons. Balance a combustion reaction A combustion reaction is an exothermic oxidation reaction in which an organic substrate (such as a hydrocarbon) reacts with elemental oxygen to form two oxygen-containing products (carbon dioxide and water). Due to their exothermic nature, combustion reactions of these nutrients are good sources of energy, which can then be used for other biological processes. Part A Enter a balanced equation for the complete combustion of linoleic acid (C18H32O2). Express your answer as a chemical formula