The New Science of Life
Chapter 24
Great Idea:Our new understanding of genetic mechanisms is leading to enormous technological advances in
medicine and other aspects of our lives.
Chapter Outline
• The Technology of Genes• Stem Cells, Cloning, and
Regenerative Medicine• The New Face of Medicine• Unraveling the Past: Mitochondrial
DNA
The Technology of Genes
Genetic Engineering
• Genetic engineering– Foreign genes inserted– Existing genes altered
• Technique– Restriction enzymes cut DNA– Another DNA strand binds– New gene is expressed
• Examples– Insulin– Agriculture
• GMO– DOA– FDA– EPA
• Bioterrorism
DNA Fingerprinting
• DNA fingerprinting– Analysis of DNA in
human tissue– Uses
• identify criminals • identify victims
• Process– Analyze DNA sections
for repeats– Compare to individual
of interest• VNTR• STR
Stem Cells, Cloning, and Regenerative Medicine
Stem Cells, Cloning, and Regenerative Medicine
• Gene Control– Genes on or off– Produce only copies
• Early development– Pluripotent
• Develop into any cell in body• Development
– Blastocyst• Outer cells: placenta• Inner cells: embryonic stem cells
– Gastrula • Not pluripotent• Differentiation
– Adulthood• Somatic or adult stem cells
• Stem Cell Line – Reproduce without differentiation
The New Face of Medicine
Computer-Assisted Drug Design
• Medicine– One or more molecules– Bond to specific molecules– Change cellular chemistry
• Research– Previous
• Search in nature– Current
• Use molecular techniques• Design drugs from scratch
• CADD– Example
• Protease inhibitors
Cancer-A Different Kind of Genetic Disease
• Normal Cell– guardianship
• Cancer– Cells reproduce without
restraint• Due to genetic defect• Usually 5-6 damaged genes
– Collection of diseases• Genetic defects
– Increase cancer probability– Lifetime risk >80%
• Cure– Surgery, radiation,
chemotherapy– Gene therapy
Gene Therapy
• Gene therapy– Replace defective gene
with healthy gene– In vivo– In vitro
• Example– SCID
• Problems– Genes inserted randomly– No proteins made
• Therapeutic viruses
DNA Repair in the Cell
• Damage– Outside cell
• Human developed• Nature
– Inside cell
• Repair mechanisms– Point defect
• Enzymes remove section
– Mismatch • Remove length of DNA• Reconstruct section
Unraveling the Past:Mitochondrial DNA
Unraveling the Past:Mitochondrial DNA
• Mitochondria– Independent DNA
(mtDNA)– Single loop– 37 genes– Non-coding section
• 1000 base pairs• Use to study human
evolution
– All mitochondria from mother
