‌‌Have you ever thought of what is going on inside your body at any given time? There is a lot of movement and bombardment of substances across the length and breadth of the human body. These movements are known as chemical reactions. Our body is made up of many systems, each undergoing a herculean task to make sure you are physically sound for the day to day activity. The reaction occurring in the body is sped up by enzymes.‌‌Our body is always in a continuous process of breaking complex molecules down for smaller and simpler ones. This process is termed catalysis. That is the chemical breakdown of larger and complex molecules or substances into simple and useable forms in the body’s cells. These break down most a times take place for a long time, for which living things can’t wait for that time since their lives depend on this reaction. For this reason, enzymes play the role of speeding the process and making it efficient.



AN ENZYME IS a biological agent or catalyst that speeds up the rate of biochemical reactions in living organisms.
‌‌A CATALYST is any substance that speeds the rate of chemical reactions. From the two definitions, we can establish the relation that enzymes are a subset of catalyst that functions in only living organisms.
‌‌CATALYSIS is a type of reaction in which larger molecules are broken down into smaller and simple molecules with the help of an enzyme to shed up its rete. The type of catalysis that occur in the human body is called biological catalysis. An example is during digestion when large food molecules are broken into smaller ones with the help of the digestive enzymes in the gut of animals.

‌‌HOW ENZYME CATALYSIS OCCURS‌‌For two substances or reactance to form a product, the reactant molecules have to attain a specific energy quantum. This energy is what every reactant needs to form a product without this there is no reaction. The minimum energy reactant molecules must have to form a product is called ACTIVATION ENERGY.

‌‌Enzymes function by binding to the reactant of the reaction, these form an enzyme-substrate complex. After binding the substrates are recruited to the active site of the enzyme where the process of catalysis occurs. The enzyme interacts with the reacting molecules by lowering the activation energy of the reaction allowing them to form a product with a minimum lower energy. After attaining this energy, intermediates maybe form before the final products.

‌‌At the end of the catalysis process, two main products are produced that is the enzymes and the final product. The final product can be more than one. When it happens that way one becomes the main product and the others become the by-products. Note that we again produced enzyme at the end of the reaction meaning that the enzyme was not used in the reaction. This is one of the main properties of an enzyme that is not consumed in the phase of the reaction.


  1. MOST ENZYMES REQUIRE COFACTORS TO FUNCTION: The efficiency of most biological catalysts is determined by another molecular called COFACTORS. A COFACTOR is a molecule that binds to the active site of an enzyme that helps enzymes function. An enzyme cofactor complex is called a holoenzyme. Which is the activated form of the enzyme. An inactive form of an enzyme is called apoenzyme. Which is an enzyme without a cofactor.‌‌FUNCTIONS OF A COFACTOR‌‌• Facilitate the recruitment of substrate onto the active site‌‌• They are the centre of the biochemical reaction.‌‌• Ensure stability of the enzyme.
  2. ENZYMES ARE NOT USED UP IN REACTION: As stated early on, at the end of any enzyme catalysts biochemical reaction, the catalyst is not consumed. The same quantity of enzyme at the beginning and end of the reaction. Hence enzymes can be reusable.
  3. ENZYMES LOWER THE ACTIVATION ENERGY OF THE REACTION: Enzymes create a new barrier of lower energy allowing products to cross even with a small amount of energy. With this more substrates can transition the activated complex. The activation energy is lowered by creating and new reaction pathway of lower energy. Hence diverting the substrate to a more energy-efficient pathway.
  4. THEY ARE SUBSTRATE AND REACTION SPECIFIC: Each enzyme has its substrate and the type of reaction is catalysis. The nature of enzymes is such a way that it breaks down a particular substance or molecule. Without that enzyme, a reaction can’t occur.
  5. ENZYMES ARE PH SPECIFIC. Every enzyme has a particular range of hydrogen ion concentration it functions best. Some catalysis in acid media others in basic media but not both. Even in acidic media, some prefer high acidity others like low acid concentration.



Enzymes only work in a living organism by speeding up the various reactions they catalase. Example SALIVARY AMYLASE. These are the enzymes found in the saliva. It aids in the catalysis of carbohydrates to maltose (sugar). It is the reason why after chewing carbohydrate food such as yam, you taste sugar in your in you mouth. As it is PH specific, it functions only in basic media. The saliva contains basic compounds to allow amylase function.


Our body continuously undergoes hundreds of reactions at any given time. These reactions there are very slow and time-wasting. To speed up their rate the body of all living things produces enzymes that help speed up the rate of this reaction. This ensures efficiency and increased productivity of organisms. Enzymes are substrate specific, require coenzyme to function, are also sensitive to the acidity or basicity of the solution etc. Note that coenzymes are a requirement for the function of most biological catalysts. The main function of enzymes is to allow the reaction to progress in a more energy-efficient pathway by lowering the activation energy to allow more and more products to be formed


1) NCBI.nlm.NIH.           the central role of enzymes as biological catalysts


2) pubs .asc. org.       Chemical basics of enzyme catalysis


3) infiniteabiotech.com.    principles of enzyme catalysis