Is Enzyme A Catalyst: 7 Facts You Should Know


In this post, you will find the information about is enzyme a catalyst, their examples and detailed facts around it.

Is enzyme a catalyst, enzyme can catalyze the biochemical reactions even in a small concentration. They speedup the reaction as catalyst does, without being consumed during the reaction.

Are catalyst and enzymes the same?

Catalyst and enzymes are different, catalyst can be any substance that induces the change in the rate of reaction. While enzymes are proteinaceous in nature usually secreted by living cells to catalyze the specific reaction without altering themselves in the reaction.

Catalysis is a process of change in the rate of  reaction with the help of specific small amount of substance called catalyst. If the rate of reaction goes up, the catalyst is considered to be positive. The catalyst is negative, if the change in the rate of reaction goes down. Catalyst working in biological system are considered to be biocatalyst or enzymes.

How does an enzyme act as a catalyst?

Enzymes act as biocatalyst in biological reaction taking place inside the living organism. Enzymes are usually formed in the living cells during the reaction. They catalyze the biochemical reactions but never initiate the reaction.

is enzyme a catalyst
Three dimensional structure of an enzyme from Wikipedia

They function as to speedup the biochemical reaction to attain equilibrium quite early. They are neither consumed nor changes in the biochemical reaction. They can function and catalyze the reaction in both directions i.e., reverse reactions. Even a minimum concentration of enzymes if sufficient to carryout biochemical reaction.

Where do enzymes act as catalyst ?

In biological systems , enzymes act as a catalyst that increases the chemical reaction by lowering the activation energy. Biochemical reactions take place in cells require lots of energy. But, energy is a limiting factor and cell use it very efficiently.

To carry out biological reactions in the cell, enzymes are produced and they act as catalyst to boost up the reaction by using small amount of energy, enzymes conserves the energy. And they are not consumed in the reaction but can be used again and again without exploiting themselves.

Why enzymes are catalyst ?

Enzymes are catalyst because they bring about the change in the rate of reaction without exploiting themselves in the reaction. Enzymes are proteinaceous in nature usually secreted by living cells to catalyze the specific reaction without altering themselves in the reaction.

If the rate of reaction goes up, the catalyst is considered to be positive. The catalyst is negative, if the change in the rate of reaction goes down. Catalyst working in biological system are considered to be biocatalyst or enzymes.

Are all enzymes a catalyst ?

All enzymes are considered as catalyst because both enzyme and catalyst increases the rate of reaction without exploiting themselves in the reaction. Catalyst are usually inorganic substances while enzymes are organic in nature. Except few, all enzymes are proteinaceous.

They function as to speedup the biochemical reaction to attain equilibrium quite early. They are neither consumed nor changes in the biochemical reaction. They can function and catalyze the reaction in both directions i.e., reverse reactions. Even a minimum concentration of enzymes if sufficient to carryout biochemical reaction.

Examples of enzymes as a catalyst

There are two groups in which enzymes are divided, desmolyzing and hydrolyzing. Enzymes belonging to hydrolyzing group usually breakdown the larger molecules into smaller substances using water molecule. Examples are: amylase, maltase, sucrase, lactase etc.

Desmolyzing enzymes catalyze other reactions which do not involve hydrolysis. Examples are : Oxidases, reductases, dehydrogenases, peroxidases, aldolases, carboxylases, transphosphorylases etc.

Difference between Catalyst and Enzymes

CatalystEnzymes
They are usually inorganic substances.They are organic and except few all are proteinaceous in nature.
They are simple molecules or ions.They are complex substances with three dimensional configuration.
They are usually small in size compared to substrate and reactant.They are larger compared to substrate and reactant.
Smaller in sizeLarger in size
Having low molecular weight.Having high molecular weight.
Belongs to non-living world.Originate from living cells.
They catalyse non-biological reactions.They catalyse biochemical reactions.
They are less specific and can catalyse diverse reactions.They are highly specific in nature.
Efficiency is low.Efficiency is high.
Regulator molecules are absent.They are usually regulated by specific molecules.
They are not sensitive to the change in pHThey are highly sensitive to the change in pH.
Not influenced by temperature.Influenced by temperature, inactivated at 0oC and denatured above 45C.
They are not affected by protein poisons.Their activity is affected by protein poisons and are destroyed.
They do not have any effect of radiations.Short wave radiations can denature the enzymes.

Properties of enzymes

  • Except ribozyme, peptidyl transferase and ribonuclease-P, all are proteinaceous in nature.

  • Enzymes have high molecular weight. Pyruvate dehydrogenase has the highest molecular weight about 4,600,000 Daltons.

  • Enzymes have colloidal nature, they are usually hydrophilic colloids.

  • Enzymes are formed inside the living cells. They never initiate the reactions in biological system or even do not change the equilibria.

  • They function as to speedup the biochemical reaction to attain equilibrium quite early.

  • They are neither consumed nor changes in the biochemical reaction.

  • In a biochemical reaction, enzyme make a complex with substrate for short time, react or interact with substrate to form product and remain attach with the product for sometime. The product is released and enzyme if freed without being changed.

  • Enzymes have unchanged form, they are neither consumed nor changed during biological reactions.

  • The enzyme has reversible nature means it can catalyze the reaction in both direction. For example- malic acid is converted to fumaric acid and vice-versa with the help of fumarase enzyme.

  • Enzymes are highly specific in nature.

  • The small concentration of enzyme is capable of catalyzing biochemical reactions and same enzyme can be used time and again.

  • Carbon anhydrase is the fastest enzyme known. It has 36 million turn over number for substrate molecules changed per minute per molecule of enzyme.

  • Enzymes are highly sensitive to the temperature and pH. Most of the enzymes inactivates at 0o C or denatured above 40oC. They require a specific range of temperature and pH to operate biochemical reactions.

Similarities between enzyme and catalyst

  • The small amount of quantity is sufficient to catalyze the reaction by catalyst and enzymes.
  • They do not change the equilibrium of the reaction.
  • They function as to speedup the biochemical reaction to attain equilibrium quite early.
  • Enzymes and catalyst increases the chemical reaction by lowering the activation energy. Biochemical reactions take place in cells require lots of energy. But, energy is a limiting factor and cell use it very efficiently.
  • Both enzyme and catalyst increase the reaction velocity.
  • They both react with the substrate without being unchanged qualitatively and quantitatively, therefore they can be used over and over again.
  • Both enzymes and catalyst can catalyze the reaction in reversible manner.
  • They both form short lived complexes with substrate or reactants.
  • The product so formed by the catalyst and enzymes are not changed by them.

Conclusion

To wrap up this post, we conclude that both enzymes and catalyst can catalyze the reactions. Enzymes are proteinaceous in nature except few, but catalyst are inorganic in nature. Therefore all enzymes are catalyst but all catalyst are not enzymes.

Both have common similarities and differences. Enzymes work in a highly specific range of temperature and pH while catalyst do not, even they are not even affected by radiations. Both work as to speedup the biochemical reaction without being exploited or even do not changed their form.

Saif Ali

Hi, I am Saif Ali. I obtained my Master's degree in Microbiology and have one year of research experience in water microbiology from  National Institute of Hydrology, Roorkee. Antibiotic resistant microorganisms and soil bacteria, particularly PGPR, are my areas of interest and expertise. Currently, I'm focused on developing antibiotic alternatives. I'm always trying to discover new things from my surroundings.  My goal is to provide readers with easy-to-understand microbiology articles. If you have a bug, treat it with caution and avoid using antibiotics to combat SUPERBUGS. Let's connect via LinkedIn.

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