Have you ever wondered about how we get energy by eating food? Where does that food go at the end? Who is responsible for the digestion of the food? Well, the answer to all the above questions is enzymes. Enzymes are present in almost all living organisms and are responsible for many activities like digestion, providing immunity, the functioning of the brain, etc. If our body doesn’t have any enzyme then it will take years to digest the food we eat. Enzymes are secreted by various organs of our body and they are temperature and pH-sensitive. Also, one enzyme does not interfere with the activity of any other enzyme as they are specific in nature. We will learn more facts about enzymes below.
This brings us down to draft a simple definition of what are enzymes. Enzymes are basically proteinaceous in nature which helps in catalyzing biochemical reactions. They have a complex molecular organization and occur in living cells. In 1926 Sumner stated the proteinaceous nature of enzymes. They work by lowering the activation energy of the reaction thus the reactions are completed at a very fast pace.
Before moving forward it is important to understand the proper enzyme definition. As enzymes help in catalyzing biological reactions, therefore, they are termed biocatalysts. Enzymes are highly specific in nature and are not used up at the end of the reaction. Enzymes cannot start a chemical reaction but they help by increasing the rate of chemical reactions. They do not change the equilibrium but help by bringing the equilibrium faster. Like any other protein, enzymes also have secondary and tertiary structures. In their tertiary structure, the protein chain backbone gets folded upon itself and in this way, many crevices and pockets are formed which are then known as active sites of enzymes.
About Enzyme Function-
There are various functions of enzymes, some of them are listed below.
Enzymes are important in the process of transferring signals from one cell to another cell. In this process, a chemical or physical signal is transmitted through a cell which is governed by a series of molecular events and then a cellular response takes place.
In the process of digestion, enzymes help break down large molecules into smaller molecules because many nutritional contents like sugars, fat, and protein are present in large molecules and cannot be taken up by the human body therefore they are needed to be broken down.
Enzymes are widely used in the field of biotechnology as molecular scissors to cut DNA fragments or as polymerases to add DNA/RNA fragments.
Enzymes are also responsible for the generation of movement in the human body with the help of myosin which hydrolyzes ATP to generate energy.
The International Union of Biochemistry appointed an Enzyme commission in 1961 which helped in the nomenclature and classification of enzymes. They are divided into 6 different types of enzymes which are listed below.
Oxidoreductase/dehydrogenase: These are the enzymes that help to catalyze oxidation-reduction reactions that involve the transfer of electrons. Here one compound is oxidized and the other is reduced. Examples: oxidases, reductases, dehydrogenases, catalases.
Ligases: These enzymes are mainly responsible for bonding two substrates which then form a large molecule. They make covalent bonds. These enzymes catalyze by joining C-O, C-S, C-N, etc. bonds. Example: Ligase, RUBP carboxylase.
Transferase: As the name suggests these enzymes are responsible for catalyzing the transfer of specific substances other than hydrogen from one substrate to another. Example: Transaminase, kinase.
Hydrolases: These enzymes help by catalyzing the breakdown of large molecules into smaller molecules along with the addition of water. Example: Protease, amylase, maltase, nucleases.
Lyases: These enzymes work without the use of water molecules. They catalyze the cleavage of the substrate into two parts. When a group is removed, a double bond is formed at its place. Example: Aldolase, decarboxylase, carbonic anhydrase, etc.
Isomerase: As the name suggests these enzymes help in catalyzing the molecular structure to form isomers. They are molecules that have similar chemical formulas but different arrangements. Example: Isomerase.
We all know that enzymes play a very important role in our daily lives. They are present in almost all the functions that are performed by our body. Some of the interesting enzymes are listed below
Enzymes are very temperature-specific. They get damaged at high temperatures which are above 40 degrees celsius.
Enzymes play an important role in the digestion of food in our body. They are found in the saliva, pancreas, stomach, and small intestines.
Enzymes are even used in industries such as food processing, paper industries, and detergents.
Enzymes are also pH specific. pH around the enzymes can affect their reaction rate.
They are also concentration-specific. More concentration can help in increasing the activity of enzymes.
Enzymes are not used up in the reaction and can be used again and again.
Well, we cannot imagine our world without enzymes. Not just digestion enzymes help us to fight bacteria and diseases. As we know that bacteria and viruses have their outer coating of protein and enzymes are proteinaceous in nature therefore they help in digesting their protein coat and hence destroying the virus or bacteria.
Some more fun facts about enzymes are:-
As we grow older the concentration of enzymes in our body also decreases.
Enzymes are temperature specific but there are some enzymes that are functional even at very high temperatures like Taq polymerase. They are obtained from bacteria that thrive at hot thermal springs.
Enzymes even help us out in assisting the brain functions. Our hypothalamus requires glucose to function properly and this glucose is taken from the liver. The enzymes facilitate the activity of the liver thus assisting in the production of glucose.
From the above discussion, we can conclude that enzymes are very important for us. They are proteinaceous in nature and help us in the process of digestion, the functioning of the brain, and signal to transfer. They are pH and temperature specific and are not used up in the reaction thus they never get vanished or exhausted. Their amount in the human body decreases with the increase of age.
1. Name the Two Enzymes that are not Proteinaceous in Nature.
Answer: The two enzymes are Ribozyme which is isolated from Tetrahymena and Ribonuclease which was discovered by Altman from bacteria.
2. What Do You Understand About the Term Isoenzymes?
Answer: Isoenzymes are just the multiple molecular forms of enzymes that occur in the same organism and have the same molecular activity. There are almost 100 enzymes that are known as isoenzymes. Alpha-amylase of wheat endosperm has 16 iso-enzymes. Lactic acid dehydrogenase has 5 iso-enzymes and alcohol dehydrogenase has 4 iso-enzymes.