Biofuels for Transportation
US Department of Energy Office of Science (2007)
An FAQ-style page with overview material such as “What is biomass?”, “How much ethanol can we get from an acre of Bioenergy crops?”, “Can one gallon of ethanol displace one gallon of gasoline?” Links to many other quality resources available from the Department of Energy. 
 

Bioenergy Buzzwords

• Cell Wall: shapes plant cells and provides structural support and disease protection to plants.
• Assay: a test to determine presence and/or amount of a substance in a sample.
• Biodiesel: a fuel made from plant oils and fats, rather than cellulose or other carbohydrates (which are used to make ethanol). This can be used in cars that run on regular diesel fuel, but not gasoline.
• Cellular Respiration: a series of chemical reactions that occur in cells to capture energy from food and turn it into a form cells can use (ATP) and other byproducts. See fermentation.
• Cellulase: an enzyme that breaks cellulose into glucose
• Cellulose: the most abundant plant material. A carbohydrate made of a chain of (beta) glucose rings strung together. A major component of the cell wall.
• Corn Stover: all of the parts of corn plant (stalk, leaves, cob, etc.) excluding the grain (kernels).
• Enzyme: a protein molecule that functions as a catalyst, i.e. it helps break apart (or build) other molecules. Enzyme names always end in “ase.” So cellulase, an enzyme, breaks apart cellulose, a carbohydrate.
• Ethanol: an alcohol that can be produced by fermentation of plant material. The same alcohol found in beer, wine and spirits. Denatured ethanol is used for transportation—it is drinkable ethanol that has additives to make it undrinkable.
• Feedstock: the plants or waste products (corn grain, corn stover, switchgrass, sugar cane, wood chips, etc) used to create biofuels such as ethanol, or other industrial chemicals.
• Fermentation: a form of cellular respiration done in an environment without oxygen. Yeast and bacteria are frequently used as fermenters; they consume sugars for energy and release byproducts such as ethanol and carbon dioxide.
• Gasification or Fischer-Tropsch Synthesis: a chemical process using a great deal of energy and pressure to turn biomass directly into fuels without biological fermentation. The product is sometimes called syn-gas.
• Genome: The complete DNA sequence associated with a particular species.
• Genotype: the letter code combination for a gene (Tt vs TT)
• Glucose: a simple sugar or carbohydrate. Cellulose and starch are both broken down into glucose before fermentation into ethanol.
• Hemicellulose: a component of the cell wall, a carbohydrate, with a more branched structure than cellulose.
• Hydrolysis: process in reaction with water of breaking larger molecules into smaller ones, for example breaking cellulose into glucose.
• Lignin: A component of the cell wall. Not a carbohydrate. The intricate association of lignin and cellulose presents one of the major challenges in converting cellulose into ethanol.
• Ligno-cellulose: a combination of lignin and cellulose. This is the most complete way to speak about using the whole plant as a feedstock for biofuels.
• Phenotype: the physical appearance as a result of the gene (tall vs. short)

Commonly discussed organisms:

• Arabidopsis: a member of mustard family, commonly studied as a model organism in plants because it is very small, has a small genome and has a short life-cycle
• E. coli or Escherichia coli: bacteria studied for ethanol production, different strains of E. coli are discussed in the news as sources of food poisoning, everyone normally has helpful E. coli in their gut
• Miscanthus: a tall grass, native to Asia, being researched for ethanol feedstock
• Rhodobacter sphaeroides: a bacteria studied for hydrogen fuel cells
• Saccharomyces cerevisiae: yeast commonly used for fermentation, and the making of bread and alcoholic beverages
• Switchgrass: a native grass in Wisconsin—could be grown in dense prairie-like stands for ethanol feedstock