Molecular Biology whats in a name

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Molecular Biology - whats in a name?

• Molecular Biology was born in the middle part
  of the last century as a new discipline focused
  on understanding the molecular basis of the most
  fundamental of life processes those involving
  the reproduction and expression of genetic
  information.

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Molecular Biology Timeline
DNA discovered by F. Meischer
1869
1910
Genes on chromosomes T.H. Morgan
1941
One gene-one enzyme, Beadle Tatum
1944
DNA is genetic material Avery, Mcleod McCarty
1953
Structure of DNA Watson, Crick, Franklin, Wilkins
1961
Discovery of mRNA Brenner, Jacob Meseleson
1966
Finished unraveling the code Nirenberg Khorana
1972
Recombinant DNA made in vitro P. Berg
DNA cloned on a plasmid H. Boyer S. Cohen
1973
Discovery of reverse transcriptase H. Temin
1973
1977
Rapid DNA sequencing F. Sanger W. Gilbert
1977
Discovery of split genes Sharp, Roberts et al.
1982
Discovery of ribozymes T. Cech S. Altman
1986
Creation of PCR K. Mullis et al.
Human Genome Project Venter, Collins and many
others
2001
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The modern framework of Molecular Biology
Transcription
Processing
Translation
DNA preRNA RNA Protein
Replication Repair
folding assembly processing
DNA
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What was the first informational macromolecule?

• Proteins ?
• DNA ?
• RNA ?
• Macromolecule no longer used in modern cells ?

RNA is the only currently used macromolecule that
is both a carrier of genetic information and an
enzyme.
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The RNA World

• The RNA world hypothesis posits that there was
  a stage early in the early evolution of life that
  was dominated by RNA.
• Moreover, the functions of RNA in modern cells
  are only remnants of its previous roles.

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Possible remnants of the RNA World

• Self-splicing introns
• Rnase P (ribozyme that cleaves tRNA precursors)
• Self-cleaving viral RNAs
• Peptidyl transferase in the ribosome
• Nucleotides (ribo) involved in
• metabolism (e.g., ATP, UTP, NADH, NADPH)
• signaling (cAMP, cGMP, GTP, ITP)
• assembly of complexes (GTP and ATP)
• Energy for motility, ion pumping, etc. (ATP, GTP)

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Molecular Biology the Origin of Life

• Can we reconstruct a living reproducing cell from
  molecules using the tools concepts of molecular
  biology?

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Suggestions for success

• Read the book as much as you can.
• Print out the slides (1-2/page) and bring them to
  lecture.
• Take additional notes on the slides in lecture
  (or tape the lecture).
• Go to Discussion Sections to ask questions, and
  take quizzes to test your understanding and
  knowledge.
• Dont wait until the day before the exam to cram.