Question

There is a restriction endonuclease called EcoR I. What does ‘co’ part of it stand for?

• A. coli
• B. Colon
• C. Colon
• D. Coenzyme

Answer 1

The correct option is A coli

Definition of restriction endonucleases
Restriction endonucleases are the enzymes which cleave the DNA by digesting phosphodiester bonds at the specific sequences within the DNA. Examples include EcoR I.

Naming of the restriction enzyme
Naming of the restriction enzyme is as follows:
In the restriction enzyme EcoR I -
● The first letter in capital represents the genus of the bacteria from which it has been isolated. For example, ‘E’ represents Escherichia.
● The next two small letters represent the first two letters of the species. For example ‘co’ represents the species of the bacteria, coli.
● The next letter represents the strain of the organism. For example, ‘R’ represents the RY-13 strain of E.coli.
● The roman numeral refers to the order in which the enzymes were isolated from that strain of bacteria. For example ‘I’ represents the first restriction endonuclease discovered from this strain of Escherichia coli.
●
Coenzyme
Coenzymes are organic compounds that act as the non-protein part of the holoenzyme. They bind loosely to the apoenzyme (the protein part of the enzyme). Examples include nicotinamide adenine dinucleotide (NAD).

Colon
Colon is the longest part of the large intestine; it connects with the caecum on one side and rectum with the other side.

Coelom
Coelom is the body cavity, between the gut and the outer body wall, which is lined by mesodermal lining.

Final answer
(B) coli