Tag: enzymes classification and cofactors

Questions Related to enzymes classification and cofactors

Name the type of enzyme involved in the following reaction $S-G+{S}^{'} \longrightarrow S-{S}^{'}+G$.

  1. Dehydrogenase

  2. Transferase

  3. Hydrolase

  4. Lyase


Correct Option: B
Explanation:

Transferase is an enzyme that transfers a specific functional groups from one molecule to another. 

Enzyme catalyzing optical or geometrical rearrangement of atomic groupings without altering molecular weight or number of atom is isomerase. It converts into from one isomer to the other isomer by changing the intramolecular arrangement by forming or breaking the bond. 
Dehydrogenase is an enzyme which participates in the oxidoreductase reaction by using a electron acceptor.
Hydrolase are the enzyme which catalyses the splitting of compounds by addition of water.
Lyase is the process by which the chemical bonds are broken down by the process other than hydrolysis and oxidation. It allows the formation of new bond. 
So, the correct answer is option B.

Arginosuccinase is a .............. enzyme.

  1. Hydrolase

  2. Ligase

  3. Lyase

  4. Oxido-reductase


Correct Option: C
Explanation:

Hydrolase is a class of enzyme which act as biochemical catalysts that use water to break chemical bonds.

Ligase is an enzyme which catalyses the joining of two large molecules by forming a new bond generally accompanied by hydrolysis of a small chemical group.
Lyase is an enzyme which catalyses the breaking of C-C, C-O and C-N bonds by any methods other than hydrolysis or oxidation. Arginosuccinase is an enzyme which catalyses the breakdown of argininosuccinate producing arginine and fumarate.
Oxido-reductase is an enzyme which catalyses the transfer of electrons from the molecule of the reductant which acts as the electron donor to another molecule of the oxidant which accepts the electron.
So, the correct answer is 'Lyase'.

Which one of the following enzymes is added in many detergents that help of remove pertinacious stains from clothes?

  1. Alcalase

  2. Xylanase

  3. Peroxidase

  4. Catalase


Correct Option: A

Enzyme involved in transfer of electrons belongs to 

  1. Hydrolase

  2. Desmolase

  3. Transaminase

  4. Dehydrogenase


Correct Option: D
Explanation:

Dehydrogenase is an enzyme which participates in the oxidoreductase reaction by using an electron acceptor. It is involved in the transfer of electrons because it oxidizes a substrate by reducing it which means it transfers the electron from the substrate to an electron acceptor. Succinate dehydrogenase is an enzyme which is present in the inner mitochondrial membrane. It catalyzes the oxidation of succinate to fumarate.

So, the correct answer is option D.

Lactose metabolising enzyme, produced in the presence of lactose only is

  1. Inducible enzyme

  2. Repressible enzyme

  3. Regulatory enzyme

  4. Constitutive enzyme


Correct Option: A

Consider the following compounds.
a. Pyridoxal phosphate
b. Tetrahydrofdlate
c. Thaimine pyrophosphate
d. Lipoid acid
Which of the above belong to the coenzymes of Pyruvate dehydrogenate complex?

  1. $1$ only

  2. $2$ only

  3. Both $1$ and $2$

  4. Neither $1$ nor $2$


Correct Option: A

Match List I with List II and select the correct answer.

List-I(Enzymes) List-II(Characteristic Activity)
a. Terminal transferees $1$. Stable above $90$ degrees C
b. Polynucleotide kinesis $2$. Cleave the ends of linear DNA
c. Taq DNA polymerases $3$ Adds phosphate to $5$ OH end of DNA or RNA
d. Exonucleases $4$. Adds a number of nucleotides to $3'$ end of DNA or RNA
$5$. Regulate the level of super coiling of DNA molecule
  1. A-$5$, B-$4$, C-$1$, D-$2$

  2. A-$4$, B-$3$, C-$1$, D-$2$

  3. A-$3$, B-$4$, C-$5$, D-$1$

  4. A-$4$, B-$3$, C-$2$, D-$1$


Correct Option: A

Enzymes catalysing removal of group and formation of double bonds are 

  1. Ligases

  2. Lyases

  3. Transferases

  4. Oxidoreductases


Correct Option: B
Explanation:

Lyases is an enzyme which catalyses the joining of specified molecules or groups by a double bond. Lyases catalyze reactions where functional groups are added to break double bonds in molecules or the reverse where double bonds are formed by the removal of functional groups. So, the correct answer is option B.

Which one of the following is not a thenno stable enzyme?

  1. Taq DNA polymerase

  2. RNA polymerase

  3. Pfu DNA polymerase

  4. Vent polymerase


Correct Option: A

The catalytic power of enzyme is represented by _____________.

  1. $V _{max}$

  2. $K _{m}$ constant

  3. Turn over number

  4. Both (2) and (3)


Correct Option: A
Explanation:
The catalytic power of an enzyme is basically the enzyme’s turnover. It is generally denoted by  $V _m$$ _a$$ _x$
So, the correct answer is $V _m$$ _a$$ _x$.