Download Our new understanding of genetic mechanisms is leading to

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
A diagram of the HIV virus. The reverse
transcriptase is the enzyme that initiates
reverse transcription in the virus.
AIDS caused by the HIV virus.
The virus has RNA that enters cells with the virus
Enzymes initiate REVERSE TRANSCRIPTION
that makes DNA
The viral DNA enters healthy DNA and make more
viral DNA that assembles into new viruses.
We now understand a huge amount about how the
HIV virus works.