Presentation on theme: "Biotechnology & Genetic Engineering Web Research An overview."— Presentation transcript:
Biotechnology & Genetic Engineering Web Research An overview
Definitions 1.) Biotechnology: the manipulation of organisms (or their components) to make useful products. 2.) Genetic Engineering: the direct manipulation of genes for useful/practical purposes.
Indirect Manipulation of DNA 1.) Humans have been changing the DNA of animals & plants for thousands of years through selective breeding. a.) Selective Breeding: Choosing the parents of an organism based on desired traits and hoping the resulting organism also carries the traits.
Indirect Manipulation of DNA cont’d… b.) This is why we have so many different breeds of dogs! c.) Also, most crop plants (corn, soybeans) are around due to selective breeding of plants long ago.
Direct Manipulation of DNA The direct manipulation of genes (genetic engineering) can be applied to biotechnology. Genetic engineering and Biotechnology have a few major tools and MANY uses… a.) We will go through tools such as DNA extraction, cutting DNA, copying DNA, inserting foreign DNA. b.) We will then go through HOW these tools are practically used in applications of biotechnology.
DNA Extraction DNA extraction: the removal of DNA by breaking open cells and nuclei. a.) We did this in our lab…we extracted our own DNA using gatorade, detergent and alcohol. Once DNA is extracted, you can make many copies of a small sample using PCR.
Cutting DNA Often, samples of DNA are very large and we might not be interested in ALL the DNA. We can cut DNA into pieces using restriction enzymes.
Restriction Enzymes 1.) Proteins that are made naturally by bacteria for defense against invaders. 2.) Restriction enzymes cut DNA at specific nucleotide sequences. a.) No matter what organism the DNA sample comes from, the restriction enzyme will recognize & cut the same sequence WHEREVER it occurs in the sample of DNA. i.) If that sequence occurs 50 times in strand of DNA then the restriction enzyme will cut 50 times!
Restriction Enzymes cont’d… 3.) The result of mixing a sample of DNA with a restriction enzyme then is many DNA fragments of varying sizes. 4.) Once DNA is cut, you can use an enzyme called DNA ligase to join different fragments of DNA together.
5.) This means you can cut DNA from different organisms (using same restriction enzyme) & join it together!
Now what? Well, if we can join DNA from 2 different organisms together, we can do all sorts of interesting things…like create transgenic organisms!
Transgenic Organisms Transgenic organism: any organism that has another species DNA spliced into its own. a.) We can (and have) created bacteria that produce human proteins & hormones, goats that produce milk with human proteins, plants that make their own insecticides, bacteria that can break down oil, livestock that grows faster…and plants that glow in the dark!
How do we create transgenic organisms? Transgenic Bacteria 1.) Bacteria have plasmids: small rings of DNA, separate from the bacteria’s own chromosome. 2.) We use plasmids to insert genes into bacteria.
The bacteria can TRANSCRIBE & TRANSLATE the plasmid DNA – including the foreign DNA that was inserted. This process is used to insert human DNA into plasmids and bacteria and the bacteria can then produce HUMAN PROTEINS!
Every time the bacteria divides, the plasmid copies and divides too so you can have millions of bacteria producing human protein you can harvest! This is how insulin and growth hormone can be made for people who need them!!!!
Transgenic Eukaryotic Organisms 1.) Inserting DNA into multicellular eukaryotes is a little trickier than bacteria. 2.) Basically, you must inject the gene of interest into the embryo of the organism when it is a single, fertilized cell. a.) Or, inject it into an egg cell that you then fertilize and reinsert into a mother. 3.) If the gene is incorporated, all cells will have it & will transcribe/translate it.
4.) Transgenic eukaryotic organisms are everywhere! a.) MOST U.S. crops are transgenic and have genes inserted to increase yields and resist pests. i.) 80% soybeans ii.) 70% cotton iii.) 38% corn b.) If you don’t look for the “non-GMO” (not genetically modified) label on food then chances are IT IS genetically modified!
c. We even create transgenic livestock- such as the goats below (read the captions)
What else can we do with extracted & cut up DNA??? Well, we can visualize it using gel electrophoresis… We can use this process to look for patterns…
Practical Applications of Gel Electrophoresis Used in Forensic Science: 1.) Because our DNA sequences are different, restriction enzymes cut at different locations. a.) We end up with differently sized fragments in a gel. b.) This means we have unique banding patterns in a gel.
Practical Applications of Gel Electrophoresis cont’d… 2.) In forensics, you can take samples from a crime scene that contain DNA & compare their banding pattern on a gel with samples from the person accused of the crime. a.) If the banding pattern matches, you’ve got your culprit!
Practical Applications of Gel Electrophoresis cont’d… 3.) In the future we may have a national database of criminal DNA & be able to do PCR and gel electrophoresis at a crime scene for faster results. 4.) In addition to being used in forensics, gel electrophoresis can be used to identify different forms of genes including mutated genes that may produce faulty proteins. a.) DNA samples can be taken from fetal cells in the womb and you can determine if an offspring will have an abnormality.
What else can we do with DNA? Well, we can sequence it so we know the order of nucleotides! 1.) The entire human genome has been sequenced. a.) An organism’s genome is its complete set of DNA. 2.) This means we know the typical sequence of nucleotides for humans!
3.) How is this done? a.) Extracted DNA is placed in test tubes with DNA polymerase and a supply of nucleotides b.) Some of the nucleotides are labeled with a fluorescent dye – when they are added to a replicating DNA strand they stop replication. c.) This produces many DNA fragments of various lengths. d.) You can separate the fragments according to size using gel electrophoresis & read the sequence of nucleotides from the gel.
Cloning Technology 1.) Cloned organisms are genetically identical! They have the same DNA sequence. 2.) It’s not necessarily scary! a.) Identical twins are clones… b.) So are all the bacteria in a single colony. c.) If you take a cutting of a plant, plant it separately & it grows, you’ve made a plant clone.
Why are we interested in cloning? 1.) The idea is to combine cloning with genetic engineering. 2.) If we insert genes into bacteria or organisms and we can clone them then we can ensure that the gene of interest will be present in the offspring. a.) Sexual reproduction can be skipped so that genes aren’t mixed up and the gene we’re interested in isn’t expressed in offspring. b.) When we insert a gene into a bacteria, every time the bacteria divides, the gene is replicated and an identical copy is made.
3.) Also, it can be used for species conservation. a.) If a recently endangered or extinct species has intact DNA we could use it with cloning procedure to produce organisms of that species.
Issues with DNA Technologies… Answer the opinion questions