Restriction enzymes

Definition

Restriction enzymes are proteins that cut DNA at specific sequences, creating fragments. They are essential tools in genetic engineering and molecular cloning.

5 Must Know Facts For Your Next Test

1. Restriction enzymes recognize specific nucleotide sequences known as recognition sites.
2. They produce either blunt or sticky ends which are crucial for DNA recombination.
3. Used extensively in cloning to insert genes into plasmids.
4. Isolated originally from bacteria where they serve a defensive role against viruses.
5. Commonly used restriction enzymes include EcoRI, HindIII, and BamHI.

Review Questions

• What is the primary function of restriction enzymes in genetic engineering?
• How do restriction enzymes contribute to the process of cloning?
• Why are 'sticky ends' important in the context of DNA recombination?

Related terms

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

DNA Ligase: An enzyme that joins DNA fragments together by forming phosphodiester bonds.

Genomic Library: A collection of cloned DNA fragments that represents the entire genome of an organism.