Great Idea: Our new understanding of genetic mechanisms is ...

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14 Δεκ 2012 (πριν από 4 χρόνια και 11 μήνες)

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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.