Although people commonly refer to laundry detergent as “soap,” it is actually a synthetic combination that works very similar to soap, with some major improvements. Soap cleans because each soap molecule is made up of a hydrocarbon chain and a carboxylic group (fatty acids) which perform two important functions. The carboxylated end of the soap molecule is hydrophilic, which means it is attracted to water, while the hydrocarbon end of the molecule is both hydrophobic (water repelled) and attracts oil and grease in the dirt. While the hydrophobic end of a soap molecule sticks to dirt, the hydrophilic end sticks to water.<\/p>