Tag: enzymes classification and cofactors

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

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

  1. Bacteria - Lysozyme

  2. Plant cells - Cellulase

  3. Algae - Methylase

  4. Fungi - Chitinase
Reveal answer Fill a bubble to check yourself
C Correct answer
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'.
Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

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

  1. Hydrolases

  2. Lyases

  3. Ligases

  4. Isomerases
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.

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

Choose the type of enzyme involved in the following reaction.


$S - G + S' \longrightarrow S + S' - G$

  1. Dehydrogenase

  2. Transferase

  3. Hydrolase

  4. Lyase

  5. Isomerase
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Based on the type of reaction catalyzed, the international union of biochemist have classified enzymes into six major classes- Oxidoreductase, Transferase, Hydrolase, Lyase, Ligase and Isomerase.
Transferase is the general name for the class of enzymes that enact the transfer of specific functional groups (e.g. a methyl or glycosyl group) from one molecule (called the donor) to another (called the acceptor).

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

In which one of the following enzymes, is copper necessarily associated as an activator? 

  1. Carbonic anhydrase

  2. Tryptophanase

  3. Lactic dehydrogenase

  4. Tyrosinase
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Tyrosinase is a copper-containing enzyme present in plant and animal tissues that catalyzes the production of melanin and other pigments from tyrosine by oxidation, as in the blackening of a peeled or sliced potato exposed to air. In animals it is found inside melanosomes which are synthesised in the skin melanocytes.

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

The cytochromes are 

  1. Peroxidase

  2. Iron protoporphyrin

  3. Pyridine nucleotides

  4. Metal containing flavoproteins
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Cytochromes are iron-porphyrin or heme proteins discovered by MacCunn. Cytochromes are bound to inner mitochondrial membrane and are primarily responsible for the generation of ATP via mitochondrial electron transport system. Whereas all other cytochromes have iron only, the cytochrome a possesses both iron and copper. With iron it picks up electrons and through copper it hands over electrons to oxygen.

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

Which of the following is main enzyme of plasma membrane?

  1. TPPase

  2. ATPase

  3. Peptidyl transferase

  4. Catalases
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

ATPase are a class of enzymes that catalyze the dephosphorylation of ATP into ADP and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur. This process is widely used in all known forms of life. Such enzymes are integral membrane proteins anchored within biological membranes (plasma membrane), and move solutes across the membrane, typically against their concentration gradient.

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

An enzyme which catalyses the conversion of aldose sugar to ketose would be classified as

  1. Transferases

  2. Isomerases

  3. Hydrolases

  4. Ligases
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Isomerases are the enzymes which catalyse transfer of groups within molecules to yield isomeric bonds. As aldose and ketose sugars are isomers, their interconversion is catalyzed by isomerases.

Transferases will catalyze group transfer reactions. 
Hydrolases will catalyze hydrolytic reactions and ligases catalyze formation of C-C, C-S, C-O and C-N bonds by condensation reactions coupled to ATP cleavage.

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

Which one of them catalyzes oxidation-reduction reactions?

  1. Oxidase

  2. Oxidoreductase

  3. Oxygenase

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Certain enzymes carry oxidation reduction reactions. Oxidation is defined as the chemical process which involves loss of electron whereas reduction is the process in which a substrate accepts electron.
An oxygenase is any enzyme that oxidizes a substrate by transferring the oxygen from molecular oxygen O$ _2$ (as in air) to it.

An oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor.
An oxidase is any enzyme that catalyzes an oxidation-reduction reaction, especially one involving molecular oxygen (O$ _2$) as the electron acceptor.