Enzymes: Notes for UPSC Exam

Enzymes are proteins made from amino acids. It is made up of hundreds and thousands of amino acids stringed together in a very specific and unique order. Any chemical reaction inside a cell or any work that goes on inside a cell is the handiwork of enzymes inside the cell. The word enzyme was coined in 1878 by German Scientist Wilhelm Kuhne.

For more details on the exam conducted by UPSC, candidates can visit the link IAS Exam.

Visit the UPSC Previous Years’ Question Papers page to become familiar with the general pattern of the UPSC Exams:

The following links will help strengthen your UPSC preparation:

How do Enzymes function?

Enzymes act as biological catalysts (biocatalysts). Catalysts accelerate chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps.

Like all catalysts, enzymes increase the reaction rate by lowering its activation energy. Some enzymes can make their conversion of substrate to product occur many millions of times faster. An extreme example is orotidine 5′-phosphate decarboxylase, which allows a reaction that would otherwise take millions of years to occur in milliseconds.

What are the Different Types of Enzymes?

On the basis of work done at the molecular level enzymes are classified into 6 different types which are given below.

  1. Hydrolases – They break chemical bonds when water is added. There are more than 200 types of hydrolases.
  2. Oxidoreductases – They are involved in catalyzing oxidation and reduction reactions.
  3. Transferases – Involved in the transfer of functional groups from a donor molecule to an acceptor molecule.
  4. Isomerases – There are 4 different sub-categories under this. They bring about structural changes within the molecule.
  5. Ligases – An example is DNA ligase which catalyzes ligation or repair of breaks in DNA.
  6. Lyases – They are also called synthase enzymes.

What are the 5 Examples of Digestive Enzymes?

The different types of digestive enzymes are given below.

  1. Amylase – helps in breaking down large starch molecules, this enzyme is produced in the mouth.
  2. Pepsin – helps in breaking down proteins, this is produced in the stomach.
  3. Trypsin – helps in breaking down proteins, this is produced in the pancreas.
  4. Pancreatic lipase – helps in breaking down fats, once again this enzyme is produced in the pancreas.
  5. Ribonuclease and deoxyribonuclease – helps in breaking down DNA and RNA, this enzyme is also produced in Pancreas.

Enzymes:- Download PDF Here

How Many Enzymes are found in Human Cells?

There are approximately 1300 different enzymes found in human cells.

Frequently Asked Questions about Enzymes


What are enzymes used for?

Enzymes create chemical reactions in the body. They actually speed up the rate of a chemical reaction to help support life. The enzymes in the body help to perform very important tasks. These include building muscle, destroying toxins, and breaking down food particles during digestion.

What are the types of enzymes?

According to the International Union of Biochemists (I U B), enzymes are divided into six functional classes and are classified based on the type of reaction in which they are used to catalyze. The six kinds of enzymes are hydrolases, oxidoreductases, lyases, transferases, ligases and isomerases.

Visit the UPSC Syllabus page for a better understanding of the exam pattern. Related preparation materials and articles, visit the links given in the table below:

Related Links

UPSC Books UPSC Monthly Current Affairs Magazine NCERT Notes For UPSC
UPSC FAQ APPSC Notification Lord Wellesley
KPSC Exam Bharatmala MPPSC Result

Daily News


Leave a Comment

Your Mobile number and Email id will not be published.