What is an Enzyme and how does It work?
What is an Enzyme?
We will discuss “what is an enzyme and how does it works?” Enzymes are the most remarkable and highly specialized proteins that act as catalysts for biochemical reaction in living things such as animals as well as the plants. Enzymes are macromolecular biological substances which are created in the pants and animals even in the microorganism. They work as catalysts in the biochemical reactions. Enzymes accelerate as well as slow down or catalyze chemical reactions. Enzymes have unique three-dimensional shapes that very useful to fit the shapes of substrates so that they could catalyze the reactions.
- They have a high degree of specificity for their substrates,
- They accelerate chemical reactions tremendously, and
- They work in aqueous solutions under very gentle temperature and pH circumstances
How do Enzymes are really looked like?
The enzymes always work with a smaller molecule which is called substrate. The substrates bind to a region within the enzyme is called the active site of the enzyme.
How does enzyme work?
Enzymes are biological macromolecules (typically proteins) produced in the cells. They significantly speed up as well as slow down the rate of virtually all of the chemical reactions that take place within cells of both the animals as well as the plants even in the microorganisms. They play a vital role in life and provide a variety of important functions in the body of any living things, such as aiding in digestion and metabolism.
Some enzymes help break large molecules into smaller pieces that are more easily further break down into very smaller pieces by other enzymes so that the living cell can absorb it. Other kinds of enzymes help to bind two molecules together to produce a new molecule. Enzymes are highly selective catalysts, that means each enzyme only speeds up a specific reaction.
The energy which the molecules of reactants have to gain to overcome the energy barrier to reaction so that they could react with other reactants and produce the other substances (product) is called the activation energy.
An enzyme-catalyzed chemical reaction takes a different ‘route’ so the activation energy becomes smaller. Therefore the enzyme and substrate form a reaction intermediate to reduce the activation energy. Then with lower activation energy, the reaction rate between reactants become faster than the reaction rate without an enzyme as a catalyst.
A simplified graph of the reaction catalysis
Route A (red color):
- reactant 1 + reactant 2 –> product
Route B (green color):
- reactant 1 + enzyme –> intermediate
- intermediate + reactant 2 –> product + enzyme
So the enzyme bind with the substrate to form a reaction intermediate, but when this reacts with another reactant and then the intermediate breaks down as well as the enzyme reforms again to repeat the whole process again and again.
- Enzymes increase the rate of reaction by lowering the energy of activation.
- Enzymes do not influence the shift in free electricity (∆G) ; instead, they accelerate ultimately occurring responses.
- As a result of their involvement in a response, enzymes are neither consumed nor permanently modified.
The lock-and-key theory:
In the lock-and-key model, the active site of an enzyme is very specific shaped to hold specific substrates. The active site and substratum do not fit completely together in the induced-fit model. They both can alter their shape which is not rigid in this mole to bind with each other.
Whatever the case, the reactions which rate is increasing greatly — over a millionfold — once the substrates bind to the active site of the enzyme. A fresh item or molecule results from the chemical reactions. Then the product separates from the enzyme. After that, the enzyme goes on to catalyze another reactant molecule again.
Here’s an example:
When the salivary enzyme amylase binds to starch, it catalyzes hydrolysis (the breakdown of a compound due to a reaction with water), resulting in maltose, or malt sugar.
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