Tag: the origin of cells and cell division

Questions Related to the origin of cells and cell division

Enzymes catalysing removal of group and formation of double bonds are 

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

  1. Ligases

  2. Lyases

  3. Transferases

  4. Oxidoreductases

Show answer
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?

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

  1. Taq DNA polymerase

  2. RNA polymerase

  3. Pfu DNA polymerase

  4. Vent polymerase

Show answer
Correct Option: A

The catalytic power of enzyme is represented by _____________.

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

  1. $V _{max}$

  2. $K _{m}$ constant

  3. Turn over number

  4. Both (2) and (3)

Show answer
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$.

The catalytic efficiency of two different enzyme can be compared by the:

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

  1. The Kim value

  2. The pH optimum value

  3. Formation of the product

  4. Molecular size of the enzyme

Show answer
Correct Option: A
Explanation:
The $K _m$ is also known as Michaelis-Menten constant. It represents the substrate concentration at which the rate of a reaction is half the maximum rate. It is an important parameter to compare catalytic efficiency of two enzymes. Lower the $K _m$ , higher will be the catalytic rate and vice-versa.

The fastest acting enzyme in the biological kingdom is

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

  1. Lipase

  2. Amylase

  3. Carboxypeptidase

  4. Carbonic anhydrase

Show answer
Correct Option: D
Explanation:

In enzymology, turnover number is the number of substrate molecules converted to products in a given unit of time on a single enzyme molecule when the enzyme is saturated with substrate. The enzyme catalase has highest turnover number value of 40,000,000 (per second per molecule of enzyme), followed by Carbonic anhydrase 400,000 (per second per molecule of enzyme), followed by acetylcholinesterase 140,000 (per second per molecule of enzyme), followed by $\beta$-lactamase 2000 (per second per molecule of enzyme).

Match the scientists and their contribution given in the columns.


Scientists Contribution
A. Pasteur p. Beer and butter milk are products of fermentation by yeast
B. Hansen q. Diastase
C. Payen and Persoz  r. Purified rennet 
D. Waksman s. Streptomycin

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

  1. A - p, B - q, C - r, D - s

  2. A - p, B - r, C - q, D - s

  3. A - p, B - s, C - r, D - q

  4. A - s, B - r, C - q, D - p

Show answer
Correct Option: B
Explanation:

The scientists listed in question had made some of the most outstanding contributions.
Pasteur discovered fermentation.  The biochemical process carried out by yeast which results in fermented products like beer and butter milk.
The first commercial standardized rennet was introduced by Chr Hansen in 1874. At that time, rudimentary methods were used to extract animal rennet from calves or adult bovine stomachs.
Diastase was the first enzyme discovered. It was extracted from malt solution in 1833 by Anselme Payen and Jean-Franois Persoz, chemists at a French sugar factory.
Waksman was awarded the Nobel Prize in Physiology or Medicine in recognition for his discovery of streptomycin, the first antibiotic active against tuberculosis.

In 1930, John Northrop crystallized which of the following enzyme as a protein?

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

  1. Pepsin

  2. Renin

  3. Amylase

  4. Trypsin

Show answer
Correct Option: A
Explanation:
In 1930, Northrop isolated a crystalline substance from a commercial pepsin preparation, and the crystallized substance appeared to be the enzyme pepsin.

The enzyme which has EC number 4.2.1.7 is assigned to which of the following classes of enzyme?

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

  1. Hydrolases

  2. Lyases

  3. Isomerases

  4. Ligases

Show answer
Correct Option: B
Explanation:

The EC number 4.2.1.7 is assigned to the enzyme named altronate dehydratase or D-altronate hydro-lyase. This enzyme catalyses the dehydration of D-altronate and results in the formation of 2-dehydroxy-3-deoxy-D-gluconate and water. 

Thus, the answer is B, i.e., the enzyme which has EC number 4.2.1.7 is assigned to the class of Lyases.

Phosphodiesterases rapidly catalyze hydrolysis of sugar phosphate bond in nucleic acids.
The first digit of their E,C number can be

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

  1. $1$

  2. $2$

  3. $3$

  4. $6$

Show answer
Correct Option: C
Explanation:

Phosphodiesterase is a hydrolase enzyme. So, it's EC number is 3.

EC or Enzyme Commission number is numerical classification scheme for enzymes, used to classify them according to reactions they catalyze.
So, the correct  option is '3'.

In recent years, pre-soaked laundry agent (detergent) contains an enzyme

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

  1. Pepsin

  2. Flavin

  3. Amylase

  4. Subtilin

Show answer
Correct Option: D
Explanation:

Natural source of subtilin is bacteria Bacillus subtilis. Subtilisins are proteolytic enzymes mainly used in detergents and house hold cleaning products to remove proteinaceous deposits and stains.