What are enzymes

Enzymes are naturally occurring proteins that function as catalysts for the vast number of chemical reactions taking place in human body. Enzymes enable metabolic and physiological processes to take place by reducing the amount of energy needed for a chemical reactions to occur. Vital reactions would occur millions, in some instances billions, of times more slowly if not for the catalytic activity of enzymes (2) which reducing the energy needed to form products.

The enzyme stabilizes the transition state, reducing the energy needed to form products.

Figure 1. The energies of the stages of a chemical reactions. Substrates need a lot of potential energy to reach a transition state, which then decays into products. The enzyme stabilizes the transition state, reducing the energy needed to form products.

Enzymes catalyze by binding substrates, or chemical reactants, into a region of enzymes called the active site. Active site may be thought of as pockets or clefts in the enzyme into which chemical substrates fits. Since every enzyme and its active site have a unique physical conformation, enzymes have a high degree of specificity for the substrates upon which they act and the type of chemical reaction they catalyze. Enzymes are not consumed by the reaction they mediate. Once an enzyme has catalyzed a chemical reaction, it releases the altered substrates from its active site and becomes available to catalyze another reaction (1).

Diagram illustrating the induced fit model of enzyme activity.

Figure 2. Diagram illustrating the induced fit model of enzyme activity.

In human physiology, enzymes can be broadly categorized as either metabolic or digestive in function (3).

Metabolic Enzymes speed up the biochemical reactions taking place in the body's cells and tissues and underlie such essential processes as energy production, synthesis and repair of cell structures, replication and repair of genetic material, and motion. They enable us to see, hear, feel, move and think. Every organ, every tissue, and all cells in our body depend upon the reaction of metabolic enzymes and their energy factor. Metabolic enzymes are produced by the liver, pancreas, gallbladder and other organs.

Digestive Enzymes belongto a large class of enzymes known as hydrolases, which are secreted along the gastrointestinal tract to breakdown the food into nutrients and waste. This allows nutrients to be absorbed into the blood stream and the waste to be discarded. Human digestive enzymes include ptyalin, pepsin, trypsin, lipase, protease, and amylase. The body does not make cellulase, an enzyme necessary for proper digestion of fiber, so it must be introduced through the raw foods we eat.

Ongoing research into the use of enzymes for gastrointestinal conditions, nutrient malabsorption, allergies, immune dysfunction, autism spectrum disorders, an as adjunct to cancer treatment is helping to clarify the specific roles enzymes can play in treating diseases and their broader role in improving human health.