Tag: enzymes

Questions Related to enzymes

A simple enzyme is

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Succinate dehydrogenase

  2. Urease

  3. Transaminase

  4. Ribozyme

Show answer
Correct Option: A
Explanation:
Succinate dehydrogenase is a enzyme which is present in the inner mitochondrial membrane. It plays an important role in citric acid cycle and the electron transport chain.
It catalyzes the oxidation of succinate to fumarate. It is a conjugated protein as it has flavo protein which has FMN or FAD molecule as a prosthetic group.
So, the correct answer is option A.

Ribozyme was discovered by

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Kuhne

  2. Duclaux

  3. Cech et al

  4. Altman et al

Show answer
Correct Option: A
Explanation:

Ribozymes are also known as ribonucleic acid enzymes. These are RNA molecules which helps in the catalysis of a particular reaction. It was discovered in the year 1982. The RNA can act as both genetic material and can act as a biocatalyst. It acts as a part of ribosome which attaches to the amino acid during protein synthesis. Thomas R. Cech and Sidney Altman discovered catalytic properties of RNA. So, the correct answer is option D.

Hydrolytic enzymes which act on low pH are called as : -

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Protease

  2. -Amylase

  3. Hydrolases

  4. Peroxidase

Show answer
Correct Option: C
Explanation:
The stomach has low pH due to the secretion of HCl. Protease, an enzyme for digesting protein acts in low pH i.e. in the stomach. Amylase is a starch (carbohydrate) digesting enzyme and carbohydrate digestion does not occur in the stomach. All digestive enzymes are hydrolases. Peroxidase is an iron-containing enzyme, found mainly in plants but also present in leucocytes and milk, that catalyses the dehydrogenation (oxidation) of various substances in the presence of hydrogen peroxide.

So, the correct answer is 'Hydrolases'.

Coenzymes NAD and NADP contain the vitamins

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Niacin

  2. Biotin

  3. Thiamine

  4. Vitamin ${B} _{12}$

Show answer
Correct Option: A
Explanation:
Nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP) are derivatives of the B-vitamin i.e., niacin. They act as coenzymes in hundreds of redox reactions.

Enzyme urease, first crystallised by Sumner was obtained from

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Human urine

  2. Canavalia

  3. Pancratium

  4. Thalictrum

Show answer
Correct Option: A
Explanation:
Sumner crystallized an enzyme known as urease from human urine and reported that all enzymes are protein. It catalyzes the hydrolysis of urea into carbon dioxide and ammonia. John Howard Northrop and Wendell Meredith Stanley shared the noble prize with Sumner for their work on the enzyme.
Buchner in 1897, prepared a yeast extract and added sugar solution to it and observed the process of fermentation. 
So, the correct answer is option A.

Match and find the correct option.

           $I$             $II$
$(a)$ Transferases $(i)$ Epimerase
$(b)$ Hydrolases $(ii)$ Kinases
$(c)$ Lyases $(iii)$ Phosphatase
$(d)$ Isomerase $(iv)$ Fumarase
biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. $a - ii, b - iii, c - iv, d - i$

  2. $a - ii, b - iii, c - i, d - iv$

  3. $a - ii, b - i, c - iii, d - iv$

  4. $a - ii, b - iv, c - iii, d - i$

Show answer
Correct Option: A
Explanation:
A kinase is an enzyme that catalyzes the transfer of phosphate groups.  It belongs to the family of transferase. 
Phosphatase enzyme catalyzes the hydrolysis of its substrate,  it is a subcategory of hydrolases. 
Fumarase enzyme belongs to the family of lyases,  specifically hydro lyases, which cleave carbon-oxygen bonds. 
Epimerases are isomerase enzymes that catalyze the inversion of compounds. So the correct answer is A. 

Which of the following is not corretly matched for the organism and its cell wall degrading enzyme ?

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Bacteria - Lysozyme

  2. Plant cells - Cellulase

  3. Algae - Methylase

  4. Fungi - Chitinase

Show answer
Correct Option: C
Explanation:
In algae, the cell wall is made up of cellulose degraded by cellulase enzyme. Bacteria have lysozyme, plants cells have cell wall degraded by cellulose and fungi have chitinase.

So, the correct answer is 'Algae - Methylase'.

Which class of enzyme catalyzes following reaction?
$\overset { X }{ \underset { C }{ | }  } \overset { Y }{ \underset { C\longrightarrow \quad X-Y+C=C }{ | }  } $

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Hydrolases

  2. Lyases

  3. Ligases

  4. Isomerases

Show answer
Correct Option: A
Explanation:

Hydrolases are biological enzymes that catalyze the hydrolysis of a chemical reaction. They usually divide larger molecules into two smaller molecules. It is a class containing more than 200 enzymes. Some common hydrolases are esterases, proteases, lipases etc.

So, the correct option is 'Hydrolases'.

An enzyme which brings about conversion of starch into maltose is:

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. catalase

  2. maltase

  3. invertase

  4. diastase

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Correct Option: A

The formation of peptide bonds is catalysed by the enzyme ________.

biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

  1. Peptidyl transferase

  2. Endonuclease

  3. DNA ligase

  4. DNA Polymerase

Show answer
Correct Option: A