Treating Starch
how starch and cellulose are treated to allow them to be used by the yeast? One potential ethanol feedstock is starch. Starch molecules are made up of long chains of glucose molecules. Thus, starchy materials can also be fermented after breaking starch molecules into simple glucose molecules. Examples of starchy materials commonly used around the world for ethanol production include cereal grains, potato, sweet potato, and cassava.
A great amount of ethanol fuel is currently produced by starch fermentation. This starch comes from grains such as wheat and maize. Fermentation is produced by a yeast culture. The digestion of starch by yeasts is done in two stages: the starch is initially hydrolyzed in sugars by a chemical or enzymatic process then sugars are converted into alcohol and carbon dioxide by yeasts. This operation is effective and extracts the solar energy stored in the starch. * Enzymes are proteins which catalyse, or speed up, biological reactions. Enzymes usually have an -ase suffix, eg. lactase, protease, amylase and so on. Biological reactions are the reactions that occur in living things. For example, when we eat food we need to digest it. Without enzymes in our bodies, digestion could take weeks instead of a matter of hours. Enzymes are specific for a certain reaction, for example, the enzyme lactase will only work in reactions where the chemical lactose is present.
Enzymes have a structure that is called active site. Only one substance can fit into the active site to be digested, and it is the only substrate that this particular enzyme works with.
The figure above shows the function of enzymes: * The substrate enters the active site of the enzyme. * The reaction takes place. * The substrate exits the enzyme as two simpler products.
You can also think of the way enzymes work as a key and a lock, the key is the substrate and the lock is the enzyme. The key should be exactly the right shape to fit in the lock, so does the
A great amount of ethanol fuel is currently produced by starch fermentation. This starch comes from grains such as wheat and maize. Fermentation is produced by a yeast culture. The digestion of starch by yeasts is done in two stages: the starch is initially hydrolyzed in sugars by a chemical or enzymatic process then sugars are converted into alcohol and carbon dioxide by yeasts. This operation is effective and extracts the solar energy stored in the starch. * Enzymes are proteins which catalyse, or speed up, biological reactions. Enzymes usually have an -ase suffix, eg. lactase, protease, amylase and so on. Biological reactions are the reactions that occur in living things. For example, when we eat food we need to digest it. Without enzymes in our bodies, digestion could take weeks instead of a matter of hours. Enzymes are specific for a certain reaction, for example, the enzyme lactase will only work in reactions where the chemical lactose is present.
Enzymes have a structure that is called active site. Only one substance can fit into the active site to be digested, and it is the only substrate that this particular enzyme works with.
The figure above shows the function of enzymes: * The substrate enters the active site of the enzyme. * The reaction takes place. * The substrate exits the enzyme as two simpler products.
You can also think of the way enzymes work as a key and a lock, the key is the substrate and the lock is the enzyme. The key should be exactly the right shape to fit in the lock, so does the