Bio 344 Molecular Biology Old web site www

Bio 344 Molecular Biology Old web site: www. sbs. utexas. edu/herrin/ bio 344/

Suggestions for success 1. Read the book as much as you can. 2. Print out the slides (1 -2/page) and bring them to lecture. 3. Take additional notes on the slides in lecture (or tape the lecture). 4. Go to Discussion Sections to ask questions, and take quizzes to test your understanding and knowledge. 5. Don’t wait until the day before the exam to cram.

Molecular Biology - what’s 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.

Molecular Biology Timeline 1869 1910 1941 DNA discovered by F. Meischer Genes on chromosomes; T. H. Morgan One gene-one enzyme, Beadle & Tatum 1944 1953 DNA is genetic material; Avery, Mcleod& Mc. Carty 1961 Discovery of m. RNA; Brenner, Jacob & Meselson 1966 Finished unraveling the code; Nirenberg & Khorana 1972 Recombinant DNA made in vitro; P. Berg DNA cloned on a plasmid; H. Boyer & S. Cohen Discovery of reverse transcriptase; H. Temin Rapid DNA sequencing; F. Sanger & W. Gilbert Discovery of split genes; Sharp, Roberts et al. 1973 1977 1982 1986 2001 Structure of DNA; Watson, Crick, Franklin, Wilkins Discovery of ribozymes; T. Cech & S. Altman Creation of PCR; K. Mullis et al. Human Genome Project; Venter, Collins and many others

The modern framework of Molecular Biology DNA Transcription Replication & Repair DNA Processing pre. RNA Translation RNA Protein folding assembly processing RNAs and proteins mediate these processes.

Molecular Evolution • 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.

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. • Corollary: the functions of RNA in modern cells are only remnants of its previous roles.

Possible remnants of the RNA World 1. 2. 3. 4. 5. Self-splicing introns Rnase P (ribozyme that cleaves t. RNA precursors) Self-cleaving viral RNAs Peptidyl transferase in the ribosome Nucleotides (ribo) involved in: – metabolism (e. g. , ATP, UTP, NADH, NADPH) – signaling (c. AMP, c. GMP, GTP, ITP) – assembly of complexes (GTP and ATP) – Energy for motility, ion pumping, etc. (ATP, GTP)

Molecular Biology & the Origin of Life • Can we reconstruct a living, reproducing cell from molecules using the tools & concepts of molecular biology?