Tag: enzymes classification and cofactors

Questions Related to enzymes classification and cofactors

Telomerase is an enzyme which is a

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

  1. Simple protein

  2. RNA

  3. Ribonucleoprotein

  4. Repetitive DNA

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Correct Option: C
Explanation:
Telomerase is a ribonucleoprotein enzyme which adds bases at the 3' end of one strand of telomere as directed by the RNA sequence of RNA component of this enzyme.
So, the correct answer is 'Ribonucleoprotein'

Which of the following enzymes has/have heme as a prosthetic group?
(i) Catalase                            

(ii) Carboxypeptidase
(iii) Succinic dehydrogenase 

(iv) Peroxidase

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

  1. (i) Only

  2. (i) and (ii)

  3. (ii) and (iii)

  4. (iii) and (iv)

  5. (i) and (iv)

Show answer
Correct Option: E
Explanation:

Co-enzymes tightly or covalently bonded to enzymes are called prosthetic groups, e.g., pyridoxal phosphate, heme, biotin. Heme is a prosthetic group containing ferrous ion. It is important for a number of biologically important hemoproteins such as myoglobin, cytochrome oxidase, catalase and peroxidase. Thus, the correct answer is option E.

Which one of the following enzyme contains 'Mn' metallic ion as the prosthetic group?

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

  1. Phosphatase

  2. Dehydrogenase

  3. Peptidase

  4. Catalase

Show answer
Correct Option: C
Explanation:

Prosthetic groups are tightly bound cofactors. Peptidase enzymes hydrolyze peptide bonds. Peptidase enzymes require manganese ion for their activity as prosthetic group.

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

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

  1. Lactic dehydrogenase

  2. Tyrosinase

  3. Carbonic anhydrase

  4. Trytophanase

Show answer
Correct Option: B
Explanation:

Some enzymes require metal ions for their activity. Tyrosinase is a copper containing enzyme that catalyzes the production of melanin and other pigments.

Most of the digestive enzymes belong to the class of

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

  1. Lyases

  2. Hydrolases

  3. Oxidoreductases

  4. Transferases

Show answer
Correct Option: B
Explanation:

Hydrolase enzymes break large molecules into small molecules with the help of hydrogen and hydroxyl group of water molecules. The phenomenon is known as hydrolysis. Digestive enzymes in our body help to break down macromolecules of food into smaller molecules by the process of hydrolysis. So, digestive enzymes belong to the class Hydrolases. Thus, the correct option is B.

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

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Correct Option: B
Explanation:

Simple enzymes consist of only proteins and catalyze their substrate specific reactions. Urease is an enzyme which is only made up of protein and it functions to catalyze the hydrolysis of urea which results in the formation of ammonia and carbon dioxide.

Succinate dehydrogenase is an enzyme complex consisting of four polypeptides (SDH A-D) which catalyses the conversion of succinate to fumarate during cellular respiration.
Transaminase signifies a group of enzymes which catalyze transamination reaction.
Ribozymes are also called catalytic RNAs. These are RNA enzymes catalyzing peptide bonding reaction during protein synthesis.
Thus, the correct answer is 'Urease is a simple enzyme'.

Hydrolysis of starch occurs with the help of

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

  1. Sucrase

  2. Amylase

  3. Peptidase

  4. Lipase

Show answer
Correct Option: B
Explanation:

Starch is used as food reserves in plants. It is a polymer of glucose. It is formed by the attachment of glucose unit by glycosidic bonds. The basic formula of starch is (C$ _6$H$ _{10}$O$ _5$)n. 

Amylase is an enzyme which helps in the digestion of the starch. It acts on the glycosidic bonds of the starch and converts into simpler compounds. It helps in the hydrolysis of this bond. It is present in the saliva and the pancreas secretion in humans and helps in intracellular digestion of starch.
So, the correct answer is option B.

Enzymes catalysing removal of groups and formation of double bond are

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

  1. Transferases

  2. Ligases

  3. Lyases

  4. Oxidoreductases

Show answer
Correct Option: C
Explanation:

Lyase is the enzyme by which the chemical bonds are broken down by the process other than hydrolysis and oxidation. It allows the formation of new bond. 

Ligase are the enzyme which catalyzes the joining of two large molecules by formation of chemical bonds.
Oxoreductase are the enzyme which catalyzes the oxidation and reduction reaction.

Transferase involves the transfer of functional group from one molecule to the other.
So, the correct answer is option C.

Enzymes which catalyse reactions involving changes in structure of a molecule are

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

  1. Ligases

  2. Isomerases

  3. Hydrolases

  4. Transferases

Show answer
Correct Option: B
Explanation:
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. For, example glucose 6 phosphate is changed to fructose 6 phosphate by enzyme isomerase during the process of glycolysis.
Ligase is a enzyme which is used to join two molecules by establishing covalent bonds. Two DNA molecules are joined together by phosphodiester bond in presence of DNA ligase. The enzyme cannot be used for the blunt end of the DNA fragments. The nature of the bond is covalent as it involves the exchange of electrons.
Hydrolase are the enzyme which catalyses the splitting of compounds by addition of water.
Transferases helps to transfer functional group from one molecule to another.
So, the correct answer is option B.

Class of enzymes contained in lysosome

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

  1. Lyases

  2. Ligases

  3. Hydrolases

  4. Transferases

Show answer
Correct Option: C
Explanation:
Lysosomes are formed by Golgi bodies. These are membrane-bounded vesicles which contain digestive and hydrolase enzymes like glycosidases, proteases, nucleases, phospholipases, and sulfatases. The enzymes are synthesized in the mRNA transcripts exit the nucleus into the cytosol, where they are translated by rough endoplasmic reticulum. The enzymes leave the Golgi apparatus as a vesicle known as lysosomes. 
So, the correct answer is option C.