Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Replication through complementaritySlide 17Slide 18How did organisms evolve?Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Lecture 2 Thursday 8/27/09 Units and ThermodynamicsUniversity of HoustonBCHS 3304: General Biochemistry I - Fall 2009Section 21734Tuesday/Thursday 11:30 AM – 1:00 PM 102 SW Instructor: Dr. Glen B. LeggePhone: 713-743-8380Office: HSC 408Email: [email protected] hours: Tuesday and Thursday (1:00-2:00 PM) or by appointmentCourse web page:http://www.bchs.uh.edu/~glegge/teaching/The lecture notes and homework will be posted on the Webhttp://www.bchs.edu/~glegge/teaching/These notes are not a substitute for class participation. These notes are posted on the web, although they may be altered before class. They are intended to make you pay attention in class, so take these notes with you. Don’t just sit in class and just copy notes!!Read the assigned material before the lecture.Collect Homework 1 and START IT!!!Biochemistry is the study of biological processes at a chemical levelBiochemistry: Life at the Molecular LevelIntroduction to the Chemistry of LifeTHE ORIGIN OF LIFE•Universe is 15-20 billion years old –BIG BANG•Initially H2 was made then condensed to He •Over the billions of years under the right conditions complex molecules formed. •Complicated chemical reactions started occurring - intermolecular interactions and carbon based chemistry developed. From this milieu sprang the property ofLIFEThe Physical Laws of Life•Philosophers thought life contained a “vital force” or vitalism but this has been rejected by modern science.•Haldane – simple organic compounds from H2O, N2 and CO2•Urey – chemical synthesis of urea•Living organisms operate within the same physical laws that apply to physics and chemistry:•Conservation of Mass, Energy•Laws of Thermodynamics•Laws of Chemical Kinetics•Principles of Chemical ReactionsMolecular Logic of LifeThese physical laws describe several axioms that make up the Molecular Logic of Life. These axioms define: •Energy converted to work•Catalytic chemical transformations•Assembly of molecules with great complexity from simple subunits.•Complex molecules combine to form supra molecular components, organelles and finally assemble into a cell.•Store and pass on instructions for the assembly of all future generations from simple non-living precursorsLife is in constant fluxEnzyme catalyzed reactions- Substrates  Products 10-3 sec - milli secUnwinding of DNA 10-6 sec - micro sec10-15 s 10-12 s 10-9 s 10-8 s 10-6 s 10-3 s 10 s 103sfemto pico nano micro milli sec•femto fs excitation of chlorophyll•pico ps charge separation in photosynthesis•nano ns hinge protein action•10-8 10 ns fluorescence lifetime•micro s DNA unwind•milli ms enzymatic reactions•103 generation of bacteria•2.3 x 109 sec average human life spanWhat distinguishes living organisms?1) Structurally complicated and highly organized a. intricate internal structures b. many kinds of complicated molecules proteins, DNA, RNA, starches, and lipids etc. (inanimate objects sand clay are mixtures of simple compounds)2) Living organisms:a. extractb. transform ENERGYc. stored. useLiving things can extract energy from the environmentChemical: Chemoautotrophs or lithoautotrophsH2S  2H+ +S +2e-2NH3 + 4O2  2HNO3 + 2H2O4FeCO3 + O2 + 6H2O  4Fe(OH)3 + 4CO2orSunlight: PhotoautotrophsnCO2 + nH2O + h (CH2O) + nO2Energy is needed to build and maintain structuresa) mechanical energy - musclesb) chemical energy - electric eelc) osmotic energy - plant turgerd) light energy -bioluminescence3) Most characteristic attribute of living things is self-replication and self assembly it is the quintessence of the living state1 single bacteria  109 in 24 hrWith near-perfect fidelity during replication!A crystal at equilibrium grows but life at equilibrium is death!Life is a set of relationships characterizing the nature, function and interaction of biomolecules.The Essential Role of Water•H2O is the key to understanding the behavior of macromolecules. It is the solvent of life and all living transformations occur in an aqueous media- Life is thought to have arisen from the sea.•Even water-insoluble compounds such as lipid membranes derive their nature and function by their interactions with H2O.Condensation reactions•Chemical Evolution, simple molecules condense to form more complex forms (polymers)Reaction of a carboxylic acid with an amineReplication through complementarity•Specific pairing of functional groups gives rise to complementarity•More complex molecules increases chemical versatility•Complementarity makes it possible for macromolecules to replicate•Over time natural selection favored molecules that made accurate copies of themselvesHow did organisms evolve?•Blind watchmaker principle, small mutations arise at random.1. Evolution is not directed2. Evolution requires built-in sloppiness3. Evolution is constrained by the past4. Evolution is ongoing•Cell  multi cell, varied and diverse and evolutionary processes lead to diversity but life has many common themes and processes.Organic compounds found in living organisms are a product of Biological ActivityBiomolecules are selected by evolution- the fit are kept, the not fit are discarded.The more fit remain and continue to evolve.The Evolution of Cells Provided the Advantage of COMPARTMENTATIONPhylogenetic Tree of Showing Three domains of OrganismsLecture 2Thursday 8/27/09Units and