DNA Technology 1 DNA Extraction Chemical treatments cause

DNA Technology 1

DNA Extraction • Chemical treatments cause cells and nuclei to burst • The DNA is inherently sticky, sticky and can be pulled out of the mixture • This is called “spooling” DNA 2

“Spooled” DNA 3

Cutting DNA • Restriction enzymes cut DNA at specific sequences • Useful to divide DNA into manageable fragments 4

Electrophoresis • DNA can be separated based on size and charge • The phosphate groups are negatively charged • DNA is placed in a gel and electricity is run through 5

Electrophoresis • Negative DNA moves toward the positive end • Smaller fragments move farther and faster 6

Electrophoresis 7

Steps in DNA Sequencing • Many copies of a single strand of DNA are placed in a test tube • DNA polymerase is added • A mixture of nucleotides is added some of which have dye molecules attached • Each base (A, T, C, G) has a different color dye 8

Steps in DNA Sequencing • By chance, some dyed nucleotides & some regular ones are added • Dye molecules are large and stop the chain from growing 9

DNA Sequencing • The result is DNA fragments of multiple sizes with colors that can be identified 10

DNA Sequencing • After the gel separates the resulting fragments by size, we 'read' the sequence from bottom to top. 11

Copying DNA • Polymerase Chain Reaction • Also called PCR • A method of making many copies of a piece of DNA 12

Steps in Copying DNA • A DNA molecule is placed in a small test tube • DNA polymerase that can work at high temps is added 13

Steps in Copying DNA • The DNA is heated to separate the two strands • Primers, Primers short pieces of DNA complementary to the ends of the molecule to be copied, are added 14

Copying DNA • The tube is cooled, and DNA polymerase adds new bases to the separated strands 15

PCR Large amounts of DNA can be made from a small starting sample 16

Cloning • Clone a member of a group of genetically identical cells • May be produced by asexual reproduction (mitosis) 17

Cloning organisms • A body cell from one organism and an egg cell from another are fused • The resulting cell divides like a normal embryo 18

Cloning “Dolly” 19

Human Genome Project 20

Human Genome Project • Started in 1990 • Research effort to sequence all of our DNA (46 chromosomes) • Over 3. 3 billion nucleotides • Mapping every gene location (loci) • Conducted by scientists around the world 21

HGP Insights • Only 2% of human genome codes for proteins (exons) • Other 98% (introns) are non-coding • Only about 20, 000 to 25, 000 genes (expected 100, 000) • Proteome – organism’s complete set of proteins • About 8 million single nucleotide polymorphisms (SNP) – places where humans differ by a single nucleotide • About ½ of genome comes from transposons (pieces of DNA that move to different locations on chromosomes) 22

Benefits of Human Genome Project • Improvements in medical prevention of disease, gene therapies, diagnosis techniques … • Production of useful protein products for use in medicine, agriculture, bioremediation and pharmaceutical industries. • Improved bioinformatics – using computers to help in DNA sequencing … 23

Benefits of Genetic Engineering 24

Biotechnology • The use of gene science to create new products from plants and animals 25

Biotechnology Provides: • Improved food products • Medical advances • An enhanced environment 26

Herbicide Resistant Crops + CP 4 EPSPS = Roundup gene Ready • • Soybeans: Corn: Cotton: Canola: Ready Roundup Ready, Liberty Link BXN, Roundup Ready Liberty Link, Roundup 27

Biotechnology Breakthroughs • Insulin (1982) – First commercial biotech product – Reliable, inexpensive source of insulin • Rice – Enriched with beta-carotene and iron • Bananas – Containing edible hepatitis vaccine 28

Biotechnology Breakthroughs • Potatoes with higher solid content • Garlic that lowers cholesterol • Fruits and vegetables that reduce risks of cancer and heart disease 29

Environmental Benefits • Reduced pesticide use • Lower energy requirements • Cleaner water • Less soil erosion 30

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