Enzymes can be found all around us. They exist in all forms of lives, including human, plants, bacteria, and other organisms. Any living organism needs enzymes to function properly. Chemically, enzymes are naturally occurred proteins, basic function of which is to speed up the process and efficiency of a chemical reaction without being consumed in the process. In another word, an enzyme is a protein-based catalyst. Enzymes catalyze all kinds of chemical reactions that are involved in growth, blood coagulation, healing, diseases, breathing, digestion, reproduction, and many other biological activities.
Enzymes are able to do various and numerous jobs, which can be roughly sorted into two types: biological functionsand industrial applications. On the biological aspect, enzymes are instrumental substances to many functions in living organisms.
(1) They can move parts of a cell’s internal structure and reorganize them to regulate cell activities. They deliver packages from one part to another inside cells. They pull chromosomes apart when the cells undergo mitosis. They pull cilia to trigger cell movement or to help cells move mucus up your airway as a routine to keep the airway clear. Common enzymes involved in these movement mentioned above are myosin ATPase, kinesin ATPase, and dynein ATPase.
(2) They can generate energy for living organisms. Adenosine triphosphate, also known as ATP, is the main storage form of chemical energy. ATP is a charged battery that can release energy that powers biological activities. Enzymes are the transformer to turn energyinto proper chemical forms and store it in ATP molecules. Most of these enzymes are called ATP synthases, which act as ion pumps through passive transport mechanisms.
(3) They can break down large molecules into small fragments which can then be absorbed by human body easily. Many nutritional ingredients are in the form of large molecules such as sugar, proteins, and fat, which cannot be up taken easily byhuman body. Hence, these ingredients are broken down by enzymes into smaller pieces before absorption, and this process is called catabolism. Following absorption, the small molecules will be used as building blocks to refresh the body through tissue repairing, regeneration, and growth, and this process is called anabolism. Many enzymes need to be employed in catabolism and anabolism, such as amylases and proteases.
(4) In addition, enzymes are the important players in many other functions, including immune responses, hormone and neural signal transduction and regulation, and aging processes.
As for industrial applications of enzymes, some examples are summarized in the following categories:
(1) Food processing Amylases from fungi and plants are used in the production of sugars from starch in making corn syrup. Catalytic enzymes are used in breaking down raw plant tissues into dietary fibers, removing lactose from milk for lactose-intolerant consumers, and in the baking process when yeast raises the dough.
(2) Beer brewing. Many enzymes are involved in production in a brewery. These enzymes work in a chain or synergy to give the correct levels of alcohols and carbohydrates for the best quality and flavor. The list is long but not exhaustive: amylases, glucanases, proteases, beta glucanases, arabinoxylans, amyloglucosidases, and acetolactate decarboxylases.
(3) Dairy industry. Amylases, proteases, and lipases are often used to treat milk. These enzyme pre-digest carbohydrates, proteins, and fats before human consumption, so that our bodies absorbthese nutrition conveniently. Lipases are also used in ripening blue-mold cheese, and some other enzymes could be used to kill the bacteria in the milk.
(4) Meat tenderizing. As a modern culinary art, papain is often used to soften meats before cooking, which give a tender and smooth texture of the final dishes.
(5) Paper industry. Enzymes like amylases, xylanases, and cellulases can lower the viscosity of pulp and remove lignin in order to soften and brighten paper.
(6) Biofuel industry. Enzymes, such as cellulases, can assist the conversion of biomass to cellulosic ethanol, which is then used in automobile gasoline. Some esterases are also used to convert natural plant oils into hydrocarbons that can be used as or blended in fuels to reduce carbon emission.
(7) leaning industry. Proteases, amylases, lipases and cellulasesare often used in leaning products, such as laundry detergents and dish soaps to assist removal of protein, oil, and greasy stains. They can also act as fabric conditioners.
(8) Rubber industry. Catalase enzymes can convert latex into foam rubber.
(9) Molecular biology. DNA ligase and polymerases are now widely used in genetic engineering, pharmaceutical, structural biology, and also play an important role in forensic sciences.