Manipulating DNA Chapter 9 SC 912 L 16

Manipulating DNA Chapter 9 SC. 912. L. 16. 10 – Students understand the effect of biotechnology on the individual, society, and the environment.

DNA is way too small to cut with a razor, knife, or pair of scissors. This is why restriction enzymes must be used. Restriction enzymes cut DNA at specific nucleotide sequences.

The DNA fragments must be sorted according to size. In gel electrophoresis, an electrical current is used to separate DNA fragments from each other.

Restriction maps show the lengths of DNA fragments between restriction sites in a strand of DNA.

How do scientists get an amount of DNA that is large enough to be studied? Polymerase Chain Reaction (PCR) is a technique tht produces millions of copies of a specific DNA sequence in a few hours.

Instead of using helicase to unwind the DNA, PCR uses heat to separate the strands and then copies of each strand are made.

Primer – short strand of DNA that acts as a starting point for a new strand.

Unless you have an identical twin, your complete set of DNA is unique to you. Each person has a DNA fingerprint – a representation of parts of an individual’s DNA that can be used to identify a person at the molecular level.

A clone is a genetically identical copy of a gene or organism. Examples: bacteria, identical twins, sea stars, and some plants such as banana plants.

Genetic engineering – changing an organism’s DNA to give the organism new traits. Genetic Engineering is based on recombinant DNA – DNA that contains genes from more than one organism.

Bacteria contain plasmids – tiny loops of DNA that are separate from DNA within chromosomes. Plasmids also replicate on their own. Scientists can add genes to a plasmid and place that plasmid inside of a bacterium.

Bacteria with added plasmids are called transgenic bacteria. They will express the genes on that added plasmid. A transgenic organism has genes from another organism inserted into it.

Transgenic bacteria are used to produced insulin for people with diabetes. This is one way that genetic engineering has helped improve health and society.

Transgenic plants with pesticide genes can be grown more quickly to feed more people. This is another way that genetic engineering has helped decrease famine and improve health.

Some concerns about genetically modified foods include: - Could some produce allergic reactions? - Is it ethical to change the genes of an organism? - What would happen if these genes got into the “wrong” organisms? - Could making these foods decrease biodiversity?

A genome is all of an organism's genetic information. Genomics is the study of genomes within humans and other organims.

Gene sequencing is determining the order of nucleotides in DNA. Recall that the order of nucleotides within DNA determines the protein that will be translated.

The human genome has approximately ~ 3 billion basepairs and 30, 000 to 40, 000 genes. Recall that a base pair is when one nucleotide forms a hydrogen bond with another. A-T, G-C, etcetera.

The Human Genome Project has the goals of 1) mapping and sequencing all of the DNA basepairs 2) identify ALL genes within the sequence.

Bioinformatics is the use of computer databases to organize biological data.

Proteomics is the study of all the proteins that result from an organism’s genome. Recall that proteins are the result of DNA translation.

Some people have a higher risk of developing a particular disease because of their genes. We say that these people are genetically predisposed for the disease.

Genetic Screening is the process of testing DNA to determine a person’s risk of having or passing on a genetic disorder.

Gene Therapy is the replacement of a defective gene or the addition of a gene to treat a genetic disease.