Union Academy Charter School Unit 6: biotechnology Union Academy Charter School

DNA Fingerprinting DNA fingerprints are used for identification. Crime scene suspects (exact match). Paternity testing (all fragments in the baby have to come from Mom and Dad). Identifying and cataloging endangered species.

DNA Fingerprinting – practice! baby BD2? BD1? Mom

How do they make a DNA fingerprint? 1. Collect sample (from crime scene or parent). 2. Cut the DNA up into small pieces (with restriction enzyme). 3. Make a lot more sample (amplify DNA via PCR). 4. Separate the DNA fragments on a gel (via gel electrophoresis.

Restriction digest Restriction enzymes are used to break DNA apart into smaller pieces. The enzymes are specific for a certain sequence (ex. ATACG).

Polymerase chain reaction (PCR) DN A from one homologue Making more DNA! Samples are often very small so scientists need to make more before analysis. Cycle 1: 1  2 Cycle 2: 2  4 Cycle 3: 4  8 Cycle 4: 8  16 All the way to cycle ~40! DNA polymerase, primers, nucleotides First cycle 5¢ 3¢ 3¢ 5¢ 5¢ 3¢ Heating separates strands 3¢ 5¢ 5¢ 3¢ Cooling allows primers to base pair at target site and for DNA polymerase to make new DNA 3¢ 5¢ 5¢ 3¢ 3¢ 5¢ end of first cycle 5¢ 3¢ 3¢ 5¢ to second cycle 5¢ 3¢ 3¢ 5¢

Gel electrophoresis DNA samples are loaded at the top of a gel. Electricity pulls the DNA(-) towards the positive electrode. Small pieces move towards the bottom faster. Larger pieces stay towards the top.

WARM UP

Transgenic organisms Genetic engineering is the modification of DNA. Genetic engineering can be used to create transgenic organisms (containing DNA from two different species). Example: Add glowing jellyfish DNA to another animal! Of course there are much more beneficial things to make, like vitamin enriched or drought resistant crops.

Transgenic organisms - applications Adding DNA to other organisms can benefit society! Making insulin or other drugs quickly and efficiently. Making crops resistant to drought or pests. Production of larger animals and crops. Example clips: https://www.youtube.com/watch?v=ktgACq4zcAU https://www.youtube.com/watch?v=TpmNfv1jKuA

Genetically modified foods (GMOs) DNA can be added to crops or animals to increase their nutritional value or resistance to certain conditions. Plants become resistant to pests Plants create their own insecticide from within Plants increase vitamin production (golden rice) Plants resistant to drought, salt, pH imbalance etc. Animals producing their own growth factors Benefits: Feeding many more people! Ethical concerns: Disruptive to ecosystems, possible allergic reactions, gene transfer to non-target species, unknown side effects.

Transgenic organisms – how to make one! Insulin gene plasmid DNA 1. Use a restriction enzyme to cut out the gene of interest (human insulin). 2. Use the same restriction enzyme to cut the plasmid (small circular piece of bacterial DNA). 3. Seal pieces together with the enzyme DNA ligase (creating recombinant DNA). 4. Put recombinant DNA into host cell. 5. Allow host cell to multiply and produce protein based on the gene of interest (insulin). 6. Harvest the insulin and give to patients! human cell bacterial host cell cut with restriction enzyme insulin gene plasmid DNA add DNA ligase recombinant DNA bacterial host cell cell multiplies; produces insulin insulin cloned genes for insertion into another host cell insulin

The Human Genome Project Collaborative effort among scientists to map the human genome. Goal: identify location and sequence of genes on chromosomes. Helps identify if someone has a defective gene (genetic screening). Ex. Carrier for sickle cell anemia or cystic fibrosis. Precautionary measures can be taken.

Gene therapy A virus delivers “good” DNA and replaces the “bad” DNA. Used successfully in severe combined immunodeficiency and cystic fibrosis. SCID patients are helped for 10 years but can develop leukemia. CF patients have issues with their immune system attacking the virus.

Cloning Making an exact copy of an organism. Remove nucleus from an egg (23 chromosomes) Replace with nucleus from organism you want to clone (all 46 chromosomes) Let it grow to an embryo Implant into surrogate mother Clone is born

Stem cell research Stem cells are unspecialized cells that can replicate or become other cell types.

Stem cell research There are two types of stem cells: Adult stem cells: Found in organs and tissues (ex. bone marrow). Limited on the number of cell types they can become. Embryonic stem cells: Found in an embryo. Very controversial! Research is illegal in the USA.