Restriction enzymes

Definition

Restriction enzymes are proteins that cut DNA at specific sequences, creating fragments with sticky or blunt ends. They are essential tools in genetic engineering for cloning and DNA manipulation.

5 Must Know Facts For Your Next Test

1. Restriction enzymes recognize specific palindromic sequences in DNA.
2. They create either sticky ends (overhanging sequences) or blunt ends (straight cuts).
3. These enzymes are naturally found in bacteria as a defense mechanism against viruses.
4. The discovery and use of restriction enzymes revolutionized molecular biology and genetic engineering.
5. They allow for the precise insertion, deletion, or modification of genes within an organism's genome.

Review Questions

• What type of sequences do restriction enzymes recognize?
• How do restriction enzymes contribute to genetic engineering?
• What is the natural role of restriction enzymes in bacteria?

Related terms

Ligase:

An enzyme that joins two DNA fragments together by forming a covalent bond between their sugar-phosphate backbones.

Plasmid:

A small circular DNA molecule found in bacteria that can replicate independently of chromosomal DNA and is often used as a vector in genetic engineering.

Recombinant DNA:

DNA molecules formed by laboratory methods of genetic recombination to bring together genetic material from multiple sources.