Tag: the origin of cells and cell division

Quizzes (0) Questions (216)

Questions Related to the origin of cells and cell division

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

Enzymes catalysing removal of group and formation of double bonds are 

  1. Ligases

  2. Lyases

  3. Transferases

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

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

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

  1. The Kim value

  2. The pH optimum value

  3. Formation of the product

  4. Molecular size of the enzyme
Reveal answer Fill a bubble to check yourself
A Correct answer
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.
Multiple choice biology enzymes classification of enzyme enzymes classification and cofactors the origin of cells and cell division

The fastest acting enzyme in the biological kingdom is

  1. Lipase

  2. Amylase

  3. Carboxypeptidase

  4. Carbonic anhydrase
Reveal answer Fill a bubble to check yourself
D Correct answer
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).

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

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

  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
Reveal answer Fill a bubble to check yourself
B Correct answer
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.

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

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

  1. Hydrolases

  2. Lyases

  3. Isomerases

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

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

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

  1. $1$
  2. $2$
  3. $3$
  4. $6$
Reveal answer Fill a bubble to check yourself
C Correct answer
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'.

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

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

  1. Pepsin

  2. Flavin

  3. Amylase

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