SWEET REACTIONS
Creating ethanol is a complex chemical process. Plant cells contain cellulose, hemicellulose and lignin. Acids, enzymes and other chemicals break the plants down, and the result is a pure sugar solution called sucrose. At this point, scientists add yeast, and the solution heats to between 250 and 300 degrees Celsius. The yeast has an enzyme called invertase. Heat activates this, converting the sucrose into glucose and fructose. These sugars combine with another enzyme, called zymase, which converts them into ethanol. That ethanol still has lots of water, though, so the next step involves boiling. Because ethanol boils at 78.3 and water boils at 100 degrees Celsius, the ethanol boils and turns into vapour first; it can be separated from the water, condensed back to liquid form and used for biofuel.