**5. Glossary**

Biofuel: Fuel produced from crop-derived carbohydrates. Includes bioethanol produced from fermentable sugars and biodiesel produced from plant oil.

Biomass: Biological materials used for fuel or industrial production. Here, we refer to the sum of plant harvestable tissues.

Bio-based (or bio-derived) platform molecule: A chemical compound whose constituent elements originate wholly from biomass (material of biological origin. excluding fossil C sources), and that can be utilized as a building block for the production of other chemicals.

Biorefinery feedstocks/Platform chemical feedstocks: Biorafineries are typically differentiated into polvsaccharides, lignin, protein, and extractives (e.g., triglycerides and terpenes) as all are found as constituent parts within typical biomass in varying amounts.

Building block chemicals: Molecules with multiple functional groups that possess the potential to be transformed into new families of useful molecules. According to the US Department of Energy the top 12 sugar-based building blocks are: 1,4-diacids (succinic, fumaric and malic), 2,5-furan dicarboxylic acid, 3-hydroxy propionic acid, aspartic acid, glucaric acid, glutamic acid, itaconic acid, levulinic acid, 3-hydroxybutyrolactone, glycerol, sorbitol, and xylitol/ arabinitol.

Metabolic engineering: Describes the targeted modification of endogenous metabolism to control the accumulation of one or more specific products.

Sink strength: Ability of a sink organ (any organ, e.g., roots, developing seeds, or immature leaves, that imports photosynthetic assimilates) to competitively mobilize assimilates toward itself.

Synthetic biology: Aims at creating novel functional parts, modules, circuits, and/or organisms using synthetic DNA and mathematical/logical methodologies, and has been shown to be practical and useful in various biotechnological applications.
