What are enzymes?
Enzymes are proteins and are found everywhere in nature.
The first use of enzymes occurred more than 5,000 years ago, when people stored milk in animal stomachs, which contains enzymes called “rennet,” that turn milk into cheese.
This is a good example of how enzymes work as catalysts, that is, they speed up biological reactions.
Novozymes’ customers use enzymes to replace chemicals in, and improve efficiency of, a wide variety of industrial processes, for example in the manufacture of margarine, beer, yogurt, concrete, leather, textiles and ethanol, where the enzymes are not part of the end-product. Enzymes are also used directly in products such as laundry detergents, where they help remove stains and enable low-temperature washing.
Every enzyme has a specific function and no side effects
Enzymes have one function only, and work like a key that fits in a lock. Only when the right enzyme finds the right material it can work upon, does a biochemical reaction occur.
This precise correlation means you never have to worry about side effects when enzymes are added to an industrial process. For instance, when enzymes transform starch into sugar, you can be sure that is all that will happen. No other material or process will be altered or affected.
Enzymes are stable, biodegradeable and environmentally friendlyEnzymes work at low temperature and moderate pH and are far more stable catalysts than other chemicals or biological molecules, making them the most environmentally-friendly solution for industrial manufacturing. Enzymes are biodegradeable, and keep on working until they are dissolved, usually by other enzymes.
Enzymes do not become part of the final product of the biochemical reaction which they are catalyzing. When the biochemical reaction is over, the enzyme is ready to effect the same reaction on another molecule again and again. Given the right conditions, the enzyme can go on and on for as long as needed. In some production processes, this lowers costs.
When industrial enzymes leave a production plant with the waste water, the used enzymes create no hazardous waste. They do not last long in the surrounding environment as they are broken down by microorganisms found in nature.
All enzymes are proteins, but not all proteins are enzymes
Proteins are the building blocks of all living organisms. Humans, animals, plants and microorganisms are all made up of proteins. Every part of the human body is built of proteins. Proteins constitute about 80% of the dry weight of muscle, 70% of the dry weight of skin and 90% of the dry weight of blood.
Proteins can be split into two groups: structural proteins and biologically-active proteins. Structural proteins are the main constituents of our bodies e.g. collagen, which is found in bones, tendons and ligaments, and keratin, the protein of nails, hair and feathers. Biologically-active proteins catalyze biochemical reactions in cells. These are the enzymes at the heart of Novozymes' business.
What's inside an enzymes
Like all other proteins, enzymes are made of amino acids. Each enzyme is made up of between a hundred and up to a million amino acids placed like pearls on a string. Each amino acid is bonded to the next by chemical bonds. Each enzyme has its own unique sequence of amino acids, which is determined by the genes in the cells. The vast majority of enzymes are made of only 20 different kinds of amino acid. The structure and function of the enzyme is determined by the order of the amino acids.
In most enzymes, the string of amino acids is coiled and folded thousands of times to form a highly complex three-dimensional structure, which is unique to each enzyme. It is the chemical interactions between the amino acids that force the enzymes into their three-dimensional structure, which is held together by the many different links between the different amino acids.
The unique three-dimensional structure of each enzyme determines the function of the enzyme. Even slight changes in the sequence of the amino acids on the string have a huge impact on the structure and function of the protein. With just one, or perhaps a few, amino acids replaced or switched, an enzyme may not only look different, but also act differently and convert to working on other biological molecules or treating them differently.
Although enzymes are large molecules with hundreds of amino acids, only a small part of the enzyme participates in the catalysis of biochemical reactions. This is called the active site. The three-dimensional structure of the enzyme determines the appearance of the active site. The active site precisely accommodates the shape of the biological substrate (material on which it acts). The enzyme and substrate fit together like a key in a lock, and only substrates with the right shape will be transformed by the enzyme. This is what makes enzymes specific in their action.