170 likes | 281 Views
Biotechnology . Chapter 13. Recombinant DNA . Tools used Restriction enzymes Gel electrophoresis DNA ligase. Restriction enzymes. Cut double stranded DNA into smaller fragments restriction sites Sticky ends Blunt ends . Gel electrophoresis. Separate and purify DNA fragments
E N D
Biotechnology Chapter 13
Recombinant DNA • Tools used • Restriction enzymes • Gel electrophoresis • DNA ligase
Restriction enzymes • Cut double stranded DNA into smaller fragments • restriction sites • Sticky ends • Blunt ends
Gel electrophoresis • Separate and purify DNA fragments • After cutting the DNA by restriction enzymes • Placed in an electrical field • Phosphates are negatively charged so…
This causes DNA to move to the positive side of the cell • Smaller molecules can move faster than larger one • This causes DNA to separate into fragments So…
We get this information • The number of fragments • The size of the fragments • The relative abundance of a fragment
DNA ligase • Makes phosphodiester bonds between DNA fragments. • Allows recombinant DNA You will do this in lab
Cloning • Producing many identical copies of a particular DNA sequence • Transgenic cells are contain recombinant DNA
Model organisms for recombinant DNA • Bacteria • Yeast • Plant cells • Cultured animal cells
Vectors for recombinant DNA • Plasmids • Viruses
Genomic Libraries • Collection of DNA fragments that together comprise the genome of the organism. • cDNA – complementary DNA can be found in a cDNA library • Only genes from a particular tissue (snapshot)
Block translation • Antisense RNA • Used in some drugs for cancer treatment
Application • Expression vectors have all the appropriate characteristics for expression • Inducible promoter • Tissue specific promoter • Signal sequences
Medical products • Insulin • Human growth hormone
Breeding methods • The ability to identify specific genes • Ability to introduce any gene • Ability to generate new organisms quickly
Transgenic crops • Improved nutritional value • Adapted to environment
Concerns • Unnatural • Safety • Enviornmental effects