Question

While isolating DNA from bacteria, which of the following enzymes is not required?

• A. Lysozyme
• B. Ribonuclease
• C. Deoxyribonuclease
• D. Protease

Answer 1

The correct option is C Deoxyribonuclease

Lysozyme:

Lysozyme is the enzyme that degrades the bacterial cell wall. To isolate DNA, the peptidoglycan cell wall of bacteria needs to be broken. Hence, lysozyme is required at the initial steps of DNA isolation.

Ribonuclease:

Ribonucleases are the enzymes that cleave RNA into small fragments. During isolation of DNA, contamination of the DNA by RNA is eliminated by the use of ribonuclease enzymes.

Deoxyribonuclease:

Deoxyribonuclease (DNase) is the enzyme that cleaves DNA into fragments and degrades it. During the isolation of DNA, DNase is not required because it will degrade the DNA to be isolated by hydrolysing the phosphodiester bonds.

Protease:

Protease is the enzyme that degrades proteins into amino acids. During the isolation of DNA, protease is used to degrade proteins and prevent contamination.

Final answer:

c. Deoxyribonuclease