Cracking the Code of Life Genetic Engineering Chapter 14.3 and Chapter 15

DNA Replication The process of DNA making copies of itself Helicase enzyme breaks Hydrogen bonds (unzips) DNA Polymerase adds complementary nucleotides

Restriction Enzyme: Cutting DNA DNA is relatively easy to extract from cells and tissues (b/c chemically diff.) Restriction enzymes: natural chemicals that cut DNA molecules into much smaller fragments Each restriction enzyme cuts DNA at a different sequence of nucleotides.

Restriction Enzyme: Cutting DNA The EcoRI restriction enzyme recognizes the base sequence GAATTC CTTAAG EcoRI cuts each strand between the G and A bases, leaving single-stranded overhangs, called “sticky ends,” with the sequence AATT.

Sanger Method: shotgun sequencing Add special mixtures of nucleotides so you can tell A from C from G from T Allow DNA to continue replication so it adds the colored tags onto the sticky ends

Gel Electrophoresis: Separating DNA Gel electrophoresis uses electric current to separate DNA fragments by size.

The smaller the DNA fragment, the faster and farther it moves. Gel Electrophoresis: Separating DNA

The result is a pattern of bands based on fragment size. Specific stains that bind to DNA make these bands visible. Researchers can remove individual restriction fragments from the gel and study them further. Gel Electrophoresis: Separating DNA

Gel Electrophoresis How Gel Electrophoresis works

Gene Mutations: Point Mutation Point mutations include substitutions, insertions, and deletions. Occur at a SINGLE point

Gene Mutations: Insertion Tay-Sach Degenerative neurological disorder

Cystic Fibrosis: Gene Deletion Gene Deletion of just three bases Gene “CFTR”: makes the protein “cystic fibrosis transmembrane conductance regulator” Persons with CF produce thick mucus that blocks breathing, many lung infections, lifespan years

Chromosome Mutations Cri du Chat Pallister-Killian

Patenting Genes In June 2013, the U.S. Supreme Court ruled that human genes cannot be patented in the U.S. because DNA is a “product of nature”. Nothin new is created when discovering a gene so there is no intellectual property to protect. More than 4,300 human genes were patented before this ruling – and the decision invalidated those gene patents.

DNA ownership Cops asking Ancestry.com and 23andMe for access to their genetic database Cops asking Ancestry.com and 23andMe for access to their genetic database Who owns your DNA? Who has a right to access your DNA?

Ownership of your DNA Henrietta Lacks died of cervical cancer in 1951 Researchers kept her cells for research They became the most widely used cells in human research -traveling to the moon and around the world. A multi-billion dollar industry was created from production and distribution and use of those cells.

Ownership of your DNA They became the most widely used cells in human research – traveling to the moon and around the world. A multi-billion dollar industry was created from production and distribution and use of those cells. Henrietta never granted consent for her tissues to be used – and her family didn’t know about her contribution to countless scientific achievements until a journalist, Rebecca Skloot, wrote the story in 2010.

Protein Structure

The Human Genome Project 13-year, international effort with the main goals of sequencing all 3 billion base pairs of human DNA and identifying all human genes. In 1990, the United States, along with several other countries, launched the Human Genome Project. Rough draft completed in February Final draft was completed in April of 2003.

What We Have Learned Humans share 99.9% of their DNA with every other human. Humans share 50% of their genes with a banana (all life shares genes that every living thing would need)