Question

Short /Long answer type questions.
Name the category of enzymes that cut at a specific site within the DNA molecule. Give an example. Explain how do these enzymes functions. Mention their use in genetic engineering.

Answer 1

Genetic engineering is the process of making changes in the DNA of an organism resulting in the desired organism. The enzymes that are widely used in genetic engineering are restriction enzymes they may be endonucleases (cuts the DNA strand in between) and exonucleases (cuts the DNA strand at the end). They are also called as' Molecular scissors' as they cut DNA molecule at specific sites. E.g., EcoRI is a restriction enzyme that cuts the DNA molecule only at adenine and guanine bases. These enzymes have a specific restriction site on them which cuts the DNA molecule from these particular restriction sites only. There are different restriction enzymes for different restriction sites. They are very useful in genetic engineering as they cut the DNA strand at particular where desired DNA or gene are added and attached by another enzyme DNA ligase which results in the formation of the desired organism.