BIOTECHNOLOGY AP BIOLOGY 12 GORSIC
Biotechnology • Biotechnology: manipulation of organisms or their components to perform practical tasks or provide useful products • Genetic engineering: direct manipulation of genes for practical purposes
Practical DNA Technology Uses • Diagnosis of disease • Human gene therapy • Pharmaceutical products (vaccines) • Forensics • Animal husbandry (transgenic organisms) • Genetic engineering in plants • Ethical concerns?
Karotyping • Examining the chromosome to see if there is anything extra or missing or abnormal
DNA Cloning • Restriction enzymes (endonucleases): in nature, these enzymes protect bacteria from intruding DNA; they cut up the DNA (restriction); very specific • Restriction site: recognition sequence for a particular restriction enzyme • Restriction fragments: segments of DNA cut by restriction enzymes in a reproducable way • Sticky end: short extensions of restriction fragments • DNA ligase: enzyme that can join the sticky ends of DNA fragments • Cloning vector: DNA molecule that can carry foreign DNA into a cell and replicate there (usually bacterial plasmids)
Medical Applications • diagnosing diseases • detecting susceptibility of diseases • treating diseases • gene therapy – alteration of an afflicted individual’s genes
What are some of the DNA technologies used in forensic investigations? Restriction Fragment Length Polymorphism (RFLP)RFLP is a technique for analyzing the variable lengths of DNA fragments that result from digesting a DNA sample with a special kind of enzyme. This enzyme, a restriction endonuclease, cuts DNA at a specific sequence pattern know as a restriction endonuclease recognition site. PCR AnalysisPCR (polymerase chain reaction) is used to make millions of exact copies of DNA from a biological sample STR AnalysisShort tandem repeat (STR) technology is used to evaluate specific regions (loci) within nuclear DNA. The odds that two individuals will have the same 13-loci DNA profile is about one in one billion. Mitochondrial DNA AnalysisMitochondrial DNA analysis (mtDNA) can be used to examine the DNA from samples that cannot be analyzed by RFLP or STR. Y-Chromosome AnalysisThe Y chromosome is passed directly from father to son, so the analysis of genetic markers on the Y chromosome is especially useful for tracing relationships among males or for analyzing biological evidence involving multiple male contributors.
Forensic Applications • DNA fingerprinting
Environmental Cleanup • genetically engineered microbes are being used or created to… • remove heavy metals from the environment • cleanup highly toxic mining wastes • degrade chlorinated hydrocarbons in wastewater • breakdown chemical released during oil spills • breakdown toxic wastes in waste dumps
Agricultural Applications • make vaccines & growth hormones for treating farm animals • creating transgenic animals & plants
Polymerase chain reaction (PCR) • Amplification of any piece of DNA without cells (in vitro) • Materials: heat, DNA polymerase, nucleotides, single-stranded DNA primers • Applications: fossils, forensics, prenatal diagnosis, etc.
DNA Analysis • Gel electrophoresis: separates nucleic acids or proteins on the basis of size or electrical charge creating DNA bands of the same length
Restriction fragment analysis • Restriction fragment length polymorphisms (RFLPs) • Southern blotting: process that reveals sequences and the RFLPs in a DNA sequence • DNA Fingerprinting
DNA Sequencing • Determination of nucleotide sequences (Sanger method, sequencing machine) • Genomics: the study of genomes based on DNA sequences • Human Genome Project