Tag: enzymes

Questions Related to enzymes

First discovered enzyme was

  1. Isomerase

  2. Transaminase

  3. Zymase

  4. Transferase


Correct Option: C
Explanation:

Enzymes are biological catalysts, which activate various biochemical reactions of a living cell in a highly specific and precise manner. Enzymology is the study of enzymes. The name enzyme was coined by Kuhne in 1878. Pasteur recognised that some microorganisms like yeasts have got a capacity to cause fermentation in wine. In 1897, Buchner discovered that yeast extract could bring about fermentation of grape juice, like the living yeast cells. He also observed that the extract has lost its catalytic activity on boiling. He coined the word zymase for the active principle involved in the fermentation. The substance on which the enzyme acts is called substrate. Enzymes are essentially proteins but all proteins are not enzymes.

Enzymes, vitamins and hormones can be classified into a single category of biological chemicals, because all of these

  1. Are exclusively synthesized in the body of a living organism as at present.

  2. Enhance oxidative metabolism.

  3. Are conjugated proteins.

  4. Help in regulating metabolism.


Correct Option: D
Explanation:
There are more than thousand of biomolecules involve in living organisms in various biological processes. Some are vitamins, hormones, enzymes, ATP, carbohydrates, lipids, nucleic acids and proteins. Out of these main carbohydrates, proteins, lipids and nucleic acid are main biomolecules which play a vital role in living systems and mainly responsible for almost all biochemical processes. The biological molecules or biomolecules are involved in metabolic activities of living bodies such as plants and animals. Most of the biomolecules in the living cell have some broad functions like:
1. They are essential to cellular and body structure.
2. They act as energy-rich fuels during cellular respiration.
3. The molecules are used to carry information of controlling growth and biological characteristics from one generation to another.
4. They are good catalytic agents for the various chemical processes occur in cell and living body.

Ribozymes are 

  1. RNA acting as enzymes.

  2. Antibody acting as enzymes.

  3. Ribosomes acting as enzymes.

  4. None of the above.


Correct Option: A
Explanation:

Enzymes are biological catalysts which speed up the biological reactions. All metabolic reactions in a cell are catalyzed by enzymes. Almost all enzymes are proteins. There are some nucleic acids that behave like enzymes. These are called ribozymes. Ribozymes are molecules of ribonucleic acid with catalytic activity.

Which one of the following hydrolyze internal phosphodiester bonds in a polynucleotide chain?

  1. Lipase

  2. Protease

  3. Exonuclease

  4. Endonuclease


Correct Option: D
Explanation:

Endonucleases hydrolyse internal phosphodiester bonds in a polynucleotide chain. Function of nucleases is to break phosphodiester bond. A nuclease is an enzyme capable of cleaving the phosphodiester bonds between the nucleotide subunits of nucleic acids. Nucleases are usually further divided into endonucleases and exonucleases, although some of the enzymes may fall in both categories. 

Who coined the term enzyme?

  1. Pasteur

  2. Buchner

  3. Kuhne

  4. Sumner


Correct Option: C
Explanation:

Enzymes are biological catalysts, which activate various biochemical reactions of a living cell in a highly specific and precise manner. Enzymology is the study of enzymes. The name enzyme was coined by Kuhne in 1878. Pasteur recognised that some microorganisms like yeasts have got a capacity to cause fermentation in wine. In 1897, Buchner discovered that yeast extract could bring about fermentation of grape juice, like the living yeast cells. He also observed that the extract has lost its catalytic activity on boiling. He coined the word zymase for the active principle involved in the fermentation. The substance on which the enzyme acts is called substrate. Enzymes are essentially proteins but all proteins are not enzymes.

What did Kuhne do?

  1. Discovered parathyroid

  2. Coined the term enzyme

  3. Coined the term gene

  4. Discovered enzyme


Correct Option: B
Explanation:
  • In 1897, Eduard Buchner discovered that yeast extracts could ferment sugar to alcohol, proving that fermentation was promoted by molecules that continued to function when removed from cells. Frederick W. Khne called these molecules like enzymes.
    Hence, the correct option is B.

Enzymes that catalyse endergonic synthesis, coupled with exergonic hydrolysis of ATP are

  1. Ligases

  2. Isomerases

  3. Lyases

  4. Transferases


Correct Option: A
Explanation:
There are six major classes of enzymes, as follows:
(1) Oxidoreductases - Catalyze oxidationreduction reactions.
(2) Transferases - Catalyze the transfer of a functional group from a donor molecule to an acceptor molecule.
(3) Hydrolases - Catalyze hydrolysis reactions. 
(4) Isomerases - Catalyze conversion of a molecule from one isomeric form to another.
(5) Ligases - Ligases or synthetases are enzymes that catalyse endergonic synthesis, coupled with the exergonic hydrolysis of ATP
(6) Lyases - Catalyze certain reactions in which double bonds form or break.

Which enzyme act as chromosomal breaks?

  1. DNA polymerase

  2. DNase

  3. DNA ligase

  4. DNA polymerase II


Correct Option: B
Explanation:

The enzyme that cause chromosomal breaks are DNase. A deoxyribonuclease or DNase, is any enzyme that catalyzes the hydrolytic cleavage of phosphodiester linkages in the DNA backbone, thus degrading DNA. Deoxyribonucleases are one type of nuclease, a generic term for enzymes capable of hydrolising phosphodiester bonds that link nucleotides.

Enzyme were discovered for the first time in

  1. Bacteria

  2. Yeast

  3. Algae

  4. Spinach


Correct Option: B
Explanation:

Enzymes are biological catalysts, which activate various biochemical reactions of a living cell in a highly specific and precise manner. Enzymology is the study of enzymes. The name enzyme was coined by Kuhne in 1878. Pasteur recognised that some microorganisms like yeasts have got a capacity to cause fermentation in wine. In 1897, Buchner discovered that yeast extract could bring about fermentation of grape juice, like the living yeast cells. He also observed that the extract has lost its catalytic activity on boiling. He coined the word zymase for the active principle involved in the fermentation. The substance on which the enzyme acts is called substrate. Enzymes are essentially proteins but all proteins are not enzymes.

Who coined the term zymase? 

  1. Pasteur

  2. Buchner

  3. Kuhne

  4. Sumner


Correct Option: B
Explanation:

Buchner coined the term zymase for the complex of biocatalysts extracted from yeast and taking part in alcoholic fermentation. Pasteur is responsible for the process of pasteurization and Kuhne is best known today for coining the word enzyme.