Enzymes are proteins that play a vital role, helping to speed up both cellular and extracellular chemical reactions in the body.
They are crucial for digestion, maintaining organ, muscle and nerve function, reducing inflammation, detoxification, immunity, blood circulation, energy production, DNA replication and more.
But what are these biochemical reactions, and how do they help us?
Enzymes are biological catalysts
Enzymes are special proteins made up of chains of amino acids. There are different types of enzymes, and specific ones have very distinct roles for particular chemical reactions.
Their function depends on the sequence and types of amino acids they’re made up of, and the complicated 3D shape of their chain.
Their job as catalysts means they cause or speed up fundamental metabolic and digestive chemical reactions that keep us alive. During this process, enzymes remain stable and unchanged.
If an enzyme is defective somehow, through a genetic defect, deficiency or some other reason, it can cause an abnormal reaction, which can lead to metabolic dysfunction and disease.
How do enzymes work?
Enzymes are produced in the cells. They are very specific and designed for a particular substance (substrate).
The substrate interacts and reacts with the enzyme, forming an enzyme-substrate complex or new and usable ‘product’.
Once the reaction occurs, the new substrate changes shape and can no longer bind to the enzyme, and this new product can go off and do its job.
The enzyme remains unchanged and can continue latching onto more substrates, forming new products.
Enzymes are often named after the substrate they work with, having ‘ase’ at the end of their name to differentiate them as enzymes.
For example, the enzyme called amylase works with amylose, a resistant starch found in a large variety of foods.
Amylase is produced in the salivary glands and helps to break amylose down into maltose. Maltose is then broken down into glucose by the enzyme maltase in the small intestine.
This enzymatic action radically reduces the time it would otherwise take to break these starches and sugars apart.
The lock and key hypothesis
The lock and key model is one of the explanations as to how the enzyme mechanism works.
The theory is that an active site on an enzyme has a specific shape that complements and fits with its coordinating substrate. The substrate slots into and binds with the active site, and the chemical reaction occurs.
Things that can affect an enzyme's action
Body temperature and pH levels can both affect enzymes. It turns out that the optimal body temperature for humans (at around 98.6 Fahrenheit) is also ideal for enzymes to work efficiently.
pH is the measure of alkalinity and acidity. The optimum pH differs between enzymes and where they’re located in the body. For example, pepsin is found in the stomach, which has a natural pH of around 2. The enzyme trypsin breaks down proteins in the small intestine. It functions best at a more alkaline pH of 7.5 to 8.
If the temperature gets too high or the pH is too acidic or alkaline, the enzyme changes shape, becomes denatured, and can no longer attach to substrates.
Some enzymes are inactive without a cofactor, a non-protein chemical or ‘helper molecule’ which they need to function. For example, chloride ions act as a cofactor for amylase.
Types of enzymes
Generally speaking, there are three main types of enzymes, metabolic, digestive and food. The first two are produced in the body, and the others come from food.
Digestive enzymes line the digestive tract and are essential for breaking down our food so our body can use it for fuel.
Metabolic enzymes are mainly produced in the pancreas and also the liver. They aid blood circulation, detoxification, organ function, and energy production.
Food enzymes aid the digestion process. The best sources are raw, unprocessed foods. For example, bromelain – found in pineapples – helps to break proteins down into amino acids.
This is just a shallow dive into enzymes, their mechanisms and their functions.
Enzymes are responsible for a vast range of chemical reactions, they are incredibly vital, and we can’t survive without them.
By binding with and altering substrates, enzymes catalyse biological processes, speeding them up. They are integral to an enormous range of functions, including DNA replication, digestion, respiration, organ function, circulation, immunity, nerve and muscle function and beyond.
Written by Rebecca Rychlik-Cunning, Nutritional Therapist and Homeopath. Follow Rebecca on Instagram, Facebook and Medium, @rebeccabitesback.
Some enzymes are inactive without a cofactor, a non-protein chemical or ‘helper molecule’ which they need to function.