CA Lesson 1 DNA Technology PDF

Unit 3: Genetics Module 12: Biotechnology Lesson 1: DNA Technology Focus Question: What is genetic engineering and why is it useful? Textbook Page No: 74 Learning Outcomes Headline Vocabulary Headline  New Voc...

Unit 3: Genetics Module 12: Biotechnology Lesson 1: DNA Technology Focus Question: What is genetic engineering and why is it useful? Textbook Page No: 74 Learning Outcomes Headline Vocabulary Headline  New Vocabulary genetic engineering DNA ligase genome transformation restriction enzyme cloning gel electrophoresis polymerase chain reaction recombinant DNA transgenic organism plasmid  Genetic Engineering By about 1970, researchers had discovered the structure of DNA and determined the central dogma that information flowed from DNA to RNA to proteins. However, scientists did not know much about the function of individual genes. The situation changed when scientists began using genetic engineering. Genetic engineering is a way of manipulating the DNA of an organism by inserting extra DNA or inserting DNA from another organism (exogenous DNA). One example of genetic engineering uses green fluorescent protein (GFP). GFP is a protein made naturally in jellyfish. GFP causes jellyfish to turn green under ultraviolet light. Scientists have inserted the DNA for making GFP into other organisms. This makes the organisms glow.  Genetically engineered organisms are used Genetics and Biotechnology ▪ to study the expression of a particular gene. ▪ to investigate cellular processes. ▪ to study the development of a certain disease. ▪ to select traits that might be beneficial Genetically engineered bollworm to humans.  DNA Tools Genome The total DNA present in the Genetic engineering can be used to nucleus of each cell increase or decrease the expression of specific genes in selected organisms. It has many applications from human health to agriculture. It contain millions of nucleotides In order to study a specific gene, DNA tools can be used to manipulate DNA and isolate genes from the rest of the genome  DNA Tools Restriction Enzymes Restriction enzymes are proteins that recognize and bind to specific DNA sequences and cleave the DNA within that sequence. Restriction enzymes are used as powerful tools for isolating specific genes or regions of the genome. A restriction enzyme or Endonuclease cuts viral DNA into fragments after it enters the bacteria by breaking sugar phosphate back bones.  Restriction enzymes Thy are proteins were discovered in late the 1960 Found in Bacteria also called Endonuclease Function Defense against viruses -when virus enters the bacteria : Scientists used it to Restriction enzymes Isolate specific genes or - 1-Binds to viral DNA regions of the genome -create fragments of different 2-cuts the viral DNA in to fragments sizes (unique to every individual) EcoRI EcoRI is a restriction enzyme that specifically cuts DNA containing the sequence GAATTC. Sticky ends are single stranded DNA sequences at the end of fragments. They can be joined together with complementary sticky ends. Not all restriction enzymes leave sticky ends. Some restriction enzymes cut straight across both DNA strands, leaving blunt ends. DNA fragments with blunt ends can be joined to other DNA fragments with blunt ends. 1.What type of molecule is an enzyme? Protein 2.What kind of enzymes make genetic engineering possible? Restriction enzymes 3.What is the function of these enzymes? Cuts the DNA molecule in a specific place 4.Are the EcoRI ends sticky or blunt? Sticky 5.Determine where EcoR1 cut DNA sequence.  Quiz 3. Based on the sequences below, which enzyme produces a blunt end? The cut site is indicated by the *. A EagI C*GGCC G C NsiI A TGCA*T G CCGG*C T*ACGT A B EcoRI GAA*TTC D TaqI T*CG A CTT*AAG A GC*T CORRECT  GEL ELECTROPHORESIS It is a process used to separate DNA fragments according to the size of fragments by an electric current ▪When an electric current is applied, the DNA fragments move toward the positive end of the gel. The smaller fragments move farther faster than the larger ones. Known DNA fragments for identification The unique pattern created based on the size of DNA fragment can be compared to Portions of the gel containing each band can be removed for further study From the shown patterns Find the Puppy father from the DNA sample From the shown patterns Who is the biological father for the baby? From the shown patterns The criminal is….. DNA fragment(from gel ) DNA from another source Recombinant DNA  Recombinant DNA Technology What is? Importance Quantities Materials used Specific size of DNA Studying individual Need large fragments combined genes. quantities of DNA with DNA fragments molecules. from another source. Vector(Carrier) The host cell Recombinant Restriction enzyme DNA DNA ligase  Why are the plasmids used as vectors? 1-Vector(Carrier) -Because they can be cut with restriction enzymes -Transfers the recombinant DNA into a bacterial cell called the host cell. If a plasmid and a DNA -Plasmids and viruses are commonly used fragment obtained from vectors. another genome have been cleaved the same restriction What is a plasmid? enzyme, the ends of each DNA fragment will be -Small, circular, double-stranded DNA complementary and can be molecules that occur naturally in combined. bacteria and yeast cells  3-Restriction enzyme 2-The host cell -A bacterial cell that recombinant DNA transfers to it.  4-DNA ligase -Joins DNA fragments that have sticky ends, and those that have blunt ends chemically. -Normally used by cells in DNA repair and replication.  Gene cloning ▪ To make a large quantity Genetics of recombinant plasmid DNA and Biotechnology bacterial cells are mixed with recombinant plasmid DNA. ▪ Some of the bacterial cells take up the recombinant plasmid DNA through a process called transformation. What is the difference between these two cells? How Bacterial cells can be Or transformed? How can recombinant DNA transfer into bacteria? Electric pulsation or heat Temporary creates openings in the plasma membrane of the bacteria What will happen to Transformed Bacteria ? Large numbers of identical bacteria, each containing the inserted DNA molecules, can be produced through a process called cloning. To know more about gene cloning, we will study recombinant plasmid DNA with AMP mixed with bacteria How to select the bacteria which have taken up the correct piece of DNA? -The bacteria are spread onto nutrient agar. -The agar also contains antibiotic (ampicillin plates) which allows growth of only the transformed bacteria.(Why…!!!!!) Genetics and Biotechnology  Quiz 2. What is the role of this molecule in cloning? A to carry the foreign CORRECT DNA into the host cell B to identify the source of DNA as foreign C to cut the host cell’s DNA D to produce antibodies  DNA sequencing Is it useful to know the DNA sequence of molecules the DNA? -sequence of DNA DNA fragments important to Know the DNA sequence of fragments DNA fragment separate DNA sequence What is the importance of knowing the sequence of the DNA? 1-Provides scientists with valuable information for further study. 2-Predict the function of the gene. 3-Compare the gene with similar sequences from other organisms. 4-Identify mutations or errors in the DNA sequence The DNA molecules which use for sequence reaction first must be…………….into smaller …………….. using……….. …………... Why? Because the genome of most organisms are made up of millions of nucleotides. Write the materials and machine used in DNA Sequencing Materials used Machines used 1-Unknown DNA fragment 1-Gel 2-Primer Electrophoresis Serves as a starter sequence for DNA polymerase. Separates the fluorescent- tagged fragments by length. 3-DNA polymerase Bind nucleotides to form new strands. 2-An automated sequencing 4-The four nucleotides machine (A-T-G-C) Analyzed the gel and print 5-Fluorescent-tagged nucleotides out the sequence (Coloring + modifying the structure) Tagged a small amount of nucleotide and modified the structure of the nucleotide. Stop the reaction fluorescent tagged nucleotide incorporate into the newly synthesized strand Steps of DNA sequencing sequencing reaction Mix all the materials in tube 1-Scientists mix -an unknown DNA fragment, -DNA polymerase, =and 4 nucleotides (A,T,C,G) in 4 tubes. 2-In each tube, a small amount of a different nucleotide is added (these nucleotides are tagged with a fluorescent dye that changes the structure of the nucleotide. A A C G T C T G G T T G A T C G T G A A T C G C T G 3-DNA polymerase will bind nucleotides to form new strands  T T T G G G A A A G G G G G G C C C T T T T A A A C C G G G T C 4-The reaction stops when the modified nucleotide binds to the strand (this produces strands of different lengths). The sequencing reaction is complete by this step. 5-Gel electrophoresis separates Describe how the sequence of the the strands. original DNA template is determined. 6-Sequencing machine detects the color of the tagged fragments and determines the sequence of the strand. Watch the video Write The sequence of the original DNA template How have scientists Once the sequence of a DNA fragment is known, a benefited from the DNA PCR technique can be used to make millions of sequence process? copies of a specific region of DNA fragments Polymerase chain reaction (PCR) What is? Function Quantities Applications Steps Technique Makes copies of Millions of Scientific (Process) specific regions of copies. investigation: sequenced DNA. …………and……..such as AIDS Heating/ Denaturation Cooling / Annealing extending A polymerase chain reaction (PCR) technique can be used to make millions of copies of a specific region of a DNA fragment. Steps of PCR Polymerase chain reaction Mix all the materials in tube And heat the tube. Why?? The process of heating ,cooling and nucleotide incorporation is repeated 20 to 40 times Resulting in millions of copies of the original fragment  Quiz 4. Why is the polymerase chain reaction used? A to amplify DNA C to ligate DNA CORRECT B to cut DNA D to separate DNA  Genetics and Biotechnology Matching  Starter : Quiz 1. Which of the following tools or processes is NOT involved in genetic engineering? A restriction enzymes B the human genome CORRECT C gene cloning D DNA sequencing  Recombinant DNA Biotechnology technology The use of Genetic engineering Cloning DNA Find solution to problem Genetically Engineered Organisms that have a gene from another organism organisms Transgenic organisms For research For medical and agricultural purposes Transgenic bacteria Transgenic plants Transgenic animals  Transgenic animals Transgenic Transgenic Livestock Transgenic Goats Chicken and Turkeys To improve the To secret a food supply and To study diseases To be resistant to protein called human health treatment disease antithrombin III Transgenic organisms might be used as a source of organs for organ transplants To prevent human blood from forming clots during surgery Transgenic plants A variety of plants have been genetically engineered to survive extreme weather.  Transgenic bacteria Slow : the formation of ice crystals on crops Produce : (Protect from frost damage) Insulin and growth hormones Clean up : Oil spills more efficiently Substances and decompose garbage dissolve: blood clots  Quiz 5. Transgenic bacteria can do all of the following EXCEPT A produce insulin C study diseases CORRECT B clean up oil spills D decompose garbage Final assessment – Check your understanding