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