Types of Enzymes

Enzymes are the large biomolecules that are required for the numerous chemical interconversions that sustain life. They accelerate all the metabolic processes in the body and carry out a specific task. Enzymes are highly efficient, which can increase reaction rates by 100 million to 10 billion times faster than any normal chemical reaction. Due to development in recombinant technology and protein engineering, enzymes have evolved as an important molecule that has been widely used in different industrial and therapeutical purposes.

There are three main categories of enzymes: (1) metabolic enzymes, which are produced within the body; (2) digestive enzymes, which the body produces also; and (3) food enzymes.

Metabolic enzymes are responsible for running the body at the level of the blood, tissues and organs. They are required for the growth of cells and repair and maintenance of all the body's organs and tissues. Metabolic enzymes take protein, fat, and carbohydrates and transform them into the proper balance of working cells and tissues. They also remove worn-out material from the cells, keeping them clean and healthy.

Digestive enzymes aid in the digestion of food and the absorption and delivery of nutrients throughout the body. The most commonly known digestive enzymes are secreted from the pancreas into the stomach and small intestine. Each enzyme is specific to a particular compound which it breaks or synthesizes. The 3 most important enzymes for digestion are protease, which digests protein; amylase, which digests carbohydrates; and lipase, which digests fat.

Food enzymes are derived solely from raw fruits, vegetables, and supplemental sources. Like digestive enzymes, they enable the body to digest the food by breaking down the various nutrients, such as proteins, fats, carbohydrates, and vitamins and minerals, into smallest compounds that the body can absorb. They are absolutely essential in maintaining optimal health.

Overwhelming evidence shows that food enzymes play an important role by predigesting food in the upper stomach. Supplementation of food enzymes is necessary today because so much of the food is processed or cooked. Most food enzymes are destroyed at the temperatures used to cook and process food. Food enzymes are extremely sensitive to temperatures above 118 °F. When raw foods are processed or heated in any way, they may lose 100% of their enzymes activity and up to 85% of their vitamin content. Unfortunately, even the raw food might be enzyme-deficient if it was grown in nutrient-lacking soil.


To function properly, food enzymes must also work in tandem with the coenzymes of vitamins and minerals. Unlike the enzymes in raw plant foods, coenzymes are not completely destroyed by cooking. Unless the enzymes from raw food are present, the coenzymes in the food cannot be utilized to their full potential.

For all these reasons, supplementing with enzymes is crucial to achieving a more efficient digestive process and better absorption of food's nutrients.

When an animal has an enzyme deficiency, it develops many health problems. These include digestive disturbances, constipation, gas, bloating, colon problems, excess body fat, and problems as serious as heart disease. Enzyme deficiencies have been linked to premature aging and degenerative diseases as well. In fact, studies have shown that diets deficient in enzymes can cause a 30% reduction in life span. Cancer research has discovered that certain enzymes are absent in the blood and urine of many cancer patients. Lack of enzymes and the resulting malabsorption of nutrients can also cause allergic reactions, poor healing of wounds, and skin problems.

Enzyme supplements help create more energy, promote faster and easier digestion, and encourage superior nutrient absorption. The animal's digestive system works best when enzyme supplements assist in setting the nutrients free for the body to absorb and use.

Other types of enzymes include: DNA Repair Enzymes, DNA Restriction-Modification Enzymes, DNA, Catalytic, Immobilized Enzymes, Holoenzymes, Hydrolases, Isoenzymes, Isomerases, Ligases, Lyases, Multienzyme Complexes, Oxidoreductases, Penicillin-Binding Proteins, Recombinases, Catalytic RNA, Transferases.

Classes of Enzymes

The efficiency of enzymes in accelerating chemical reactions is crucial to the maintenance of life. Cells, in effect, must race against the unavoidable processes of decay, which—if left unattended—cause macromolecules to run downhill toward greater and greater disorder. If the rates of desirable reactions were not greater than the rates of competing side reactions, a cell would soon die.

A living cell contains thousands of enzymes, many of which operate at the same time and in the same small volume of the cytosol. By their catalytic action, these enzymes generate a complex web of metabolic pathways, each composed of chains of chemical reactions in which the product of one enzyme becomes the substrate of the next.

Purple raspberry growing on a raspberry cane

Enzymes can be grouped into functional classes that perform similar chemical reactions. Each type of enzyme within such a class is highly specific, catalyzing only a single type of reaction. Thus, hexokinase adds a phosphate group to d-glucose but ignores its optical isomer l-glucose; the blood-clotting enzyme thrombin cuts one type of blood protein between a particular arginine and its adjacent glycine and nowhere else, and so on.

There are six major classes of enzymes: Oxidoreductases, Transferases, Hydrolases, Lyases, Isomerases, and Ligases.

  • ATPases - hydrolyze ATP. Many proteins with a wide range of roles have an energy-harnessing ATPase activity as part of their function, for example, motor proteins such as myosin and membrane transport proteins such as the sodium–potassium pump.
  • Hydrolases - general term for enzymes that catalyze a hydrolytic cleavage reaction.
  • Isomerases - catalyze the rearrangement of bonds within a single molecule.
  • Kinases - catalyze the addition of phosphate groups to molecules. Protein kinases are an important group of kinases that attach phosphate groups to proteins.
  • Lyases - add or remove of groups to form double bonds (not by hydrolysis).
  • Ligases - ligate two substrates at the expense of ATP hydrolysis.
  • Nucleases - break down nucleic acids by hydrolyzing bonds between nucleotides.
  • Oxidoreductases - general name for enzymes that catalyze reactions in which one molecule is oxidized while the other is reduced. Enzymes of this type are often called oxidases, reductases, and dehydrogenases.
  • Phosphatases - catalyze the hydrolytic removal of a phosphate group from a molecule.
  • Polymerases - catalyze polymerization reactions such as the synthesis of DNA and RNA.
  • Proteases - break down proteins by hydrolyzing bonds between amino acids.
  • Transferases - remove groups (not including H) from substrates and transfer them to acceptor molecules (not including water)

Enzyme names typically end in "-ase," with the exception of some enzymes, such as pepsin, trypsin, thrombin and lysozyme that were discovered and named before the convention became generally accepted at the end of the nineteenth century. The common name of an enzyme usually indicates the substrate and the nature of the reaction catalyzed. For example, citrate synthase catalyzes the synthesis of citrate by a reaction between acetyl CoA and oxaloacetate.