Genetic Engineering and Biotechnology IB topics PCR and Introduction to DNA Profiling

What is genetic engineering Genes from one organism are transferred to the genome of another Also known as recombinant DNA This can happen because remember, the genetic code is universal Triplet code  amino acid Important applications Biotechnology Pharmaceuticals, medicine, agriculture, forensics

The steps of genetic engineering 1. Isolating the gene from the source gene 2. Cutting up of DNA 3. Isolating DNA 4. Vectors for cloning 5. Using plasmids as vectors

Isolating the gene from the gene source DNA is divided into genes (units of inheritance) Average of 2200 genes/chromosome vary in length, but typically thousands of bases long Each gene codes for a particular protein For genetic engineering, genes need to be isolated and identified.

Isolating continued DNA may be extracted from tissue by: Mechanically breaking up the cells Filtering off the debris Breaking down the cell membranes by treatment with detergent The protein framework is removed by incubation with a protein digesting enzyme (protease) DNA can be isolated using ethanol

Cutting up of DNA Genetic engineering began with the discovery of restriction enzymes Occur naturally in bacteria They protect against the activity of viruses by cutting up viral DNA Many different restriction enzymes have been discovered and purified to use today They cut at particular base sequences

Isolating DNA fragments Electorphoresis Process used to separate particles DNA, RNA, proteins, and amino acids Done in agarous gel (sugar) Contain tiny pores (acts like a sieve) Small particles move quicker than larger ones Also use an electric field The molecules separated also carry an electrical charge (P in DNA is negative)

Electrophoresis Animation lectrophoresis.htmlhttp:// lectrophoresis.html

Vectors for cloning Vector: an agent that transports between one organism and another Vectors are commonly found in bacteria Plasmids (type of DNA) Easily isolated and easily re-introduced Plasmids replicate independently of the chromosome, so any gene added to the plasmid is replicated many times

Plasmids as vectors Restriction enzyme cuts open the plasmid The same restriction enzyme cuts out the gene Segments are sealed back up using the enzyme ligase

DNA Profiling Exploits techniques of genetic engineering to identify a person or organism from a sample of their DNA Forensic science Crime scenes Fingerprints, fluids, hair, skin Paternity cases

Homework Due Monday, April 19 Go to Click on human identification Take notes on all four applications: Profiling Family Murder Innocence