Recombinant DNA technology/ Cloning a plasmid (Bacterial Transformation) (7.1)

Question 1

How do you create designer plasmids (recombinant plasmids)? Use of restriction enzymes. What are sticky ends?

Answer 1

Creating Designer Plasmids:

Restriction Enzymes: These are molecular scissors that cut DNA at specific sequences. They are used to cut both the plasmid and the DNA of interest at the same site, producing sticky ends (overhanging sequences of DNA) that can pair with complementary sticky ends from another DNA molecule.

(Example: If you cut a plasmid and a gene of interest with the same restriction enzyme, the sticky ends of both will be complementary, allowing them to be joined together. )

Sticky Ends: These are single-stranded overhangs created by restriction enzymes that make it easier to join two pieces of DNA. For example, a sticky end from the plasmid can bind to a complementary sticky end from a gene of interest.

Ligation: The gene of interest is inserted into the plasmid, and the DNA ligase enzyme is used to seal the sugar-phosphate backbone, creating a recombinant plasmid.

Question 2

What are recombinant plasmids use?

Answer 2

Gene Cloning and Study
Recombinant plasmids are used to clone specific genes. This allows scientists to make copies of genes for research, study their functions, and better understand genetic material.

Protein Production
They are used to produce proteins, like insulin or enzymes, by inserting a gene into a plasmid and introducing it into bacteria or other cells, which then produce the protein in large amounts.

Genetic Engineering
Recombinant plasmids enable genetic modifications in organisms (like plants, animals, or bacteria). This allows for the creation of genetically modified organisms (GMOs) with new traits, such as disease resistance or improved growth.