Inedible parts of plants are rich in cellulose
Just as living organisms use sugars as a source of fuel, when scientists look to make fuel from biological sources sugars are key to the process. Cellulose is a long molecule made by plants, and in this case long means they can have up to over 10,000 repeating units. These units are types of sugars. Around 33% of all plant matter on Earth is made of cellulose, and some species of plants can be up to 90% cellulose. This situation makes cellulose a very attractive source for sugars for biofuel. Unfortunately, cellulose isn't sugar, and the plants who made them didn't make them to be easily taken apart. Plants use cellulose mainly for structural support, and they wouldn't have much of a structure if it was easily taken apart. Fortunately, scientists like challenges and they are using natural enzymes made by some organisms (like bacteria and fungi) as models to make artificial enzymes which will release the sugars in cellulose and make them available for the manufacture of ethanol (C2H5OH) for biofuel.
An artificial cellulosome.
If you need help scratching a mental itch, use the resources below:
- What are cellulosomes?
- Through the pursuit of cellulosic biofuel scientists are learning how to make artificial enzymes for specific purposes. Can you think of any other enzymes which would be useful for scientists to produce?
- What other characteristics should a plant species have to be a good candidate for use in making cellulosic biofuel?