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One Note. Using One Note? Alan Ward. Molecular Microbiology. Resources and Communication Lecture Email Web One Note. myhiennguyenpy@gmail.com. You can read the text explaining the slide. http:// www.onenote.com. {Request to do something}. Multiple pages Viewing page 2.
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One Note Using One Note? Alan Ward
Molecular Microbiology Resources and Communication • Lecture • Email • Web • One Note myhiennguyenpy@gmail.com You can read the text explaining the slide
Multiple pages Viewing page 2 From the powerpoint Another way of looking at it They give another example of why you need Data driven discovery as well as hypothesis driven research {What is the example?}
Some thing to do Slide 1 Some commentary
Evolution What is the structure of life? Alan Ward
Evolution Depth first or breadth first Two different strategies for computer search algorithms Which is best? That heavily depends on the structure of the search tree and the number and location of solutions. If you know a solution is not far from the root of the tree, a breadth first search (BFS) might be better. If the tree is very deep and solutions are rare, depth first search (DFS) might rootle around forever, but BFS could be faster. If the tree is very wide, a BFS might need too much memory, so it might be completely impractical. If solutions are frequent but located deep in the tree, BFS could be impractical. If the search tree is very deep you will need to restrict the search depth for depth first search (DFS), anyway.
Evolution So what is the structure of living things that we are exploring? The structure of life is dictated by evolution: “Nothing in biology makes sense except in the light of evolution” (Dobzhansky)
Evolution • How did life arise? • How did it evolve? • How is it evolving now? Why did it evolve?
Evolution Why did it evolve? 1st Law of thermodynamics Energy is neither created nor destroyed but reactions, in which energy changes, still occur 2nd Law of thermodynamics Systems change from ordered to disordered but living things are highly ordered ΔG = ΔH - TΔS
Evolution Why did life evolve? 1st Law of thermodynamics Energy is neither created nor destroyed but reactions, in which energy changes, still occur (NH4)2SO4 Processes proceed from High energy to Low energy But the 1st Law of Thermodynamics Direction of chemical change but not always Energy is neither created nor destroyed often corresponds to -ΔE
2nd Law of thermodynamics Systems change from ordered to disordered Why did life evolve? ΔG = ΔH - TΔS A + B C + D [A][B] _____ ΔG = ΔGo + RT loge [C][D] Glyceraldehyde-3-P = dihydroxyacetone-P ΔGo = +1.8 kcal [G3P] = 3 x 10-6M [diOHAcP] = 2 x 10-4M ΔG = 1.8 + 1.98x10-3x298xloge(3x10-6/2x10-4) = - 0.7 kcal/mol
Early Earth Hot (>100oC) Meteorite bombardment Volcanic Gases – H2O CH4 CO2 N2 H2S/FeS HCN CO H2 virtually no O2 Energy sources Primitive atmosphere + energy (heat, UV, electric discharge) UV light Pre-biotic synthesis of bio-molecules Amino acids, purines, pyrimidines, sugars .. Polypeptides, polynucleotides
Energy and life Spontaneous direction of change Times’ arrow H2O CO2 High energy Low energy Disordered Ordered It doesn’t go backwards inorganic Organic Complex Kept warm but no net energy in Simple More ordered
Evolution Vitalism Living organisms possess a vital force that enables them to defy the laws of physics and chemistry. In 1809 Berzelius stated the theory as that organic compounds could not be synthesized in a laboratory. In 1828 Wöhler, whose mentor was Berzelius, synthesized urea, previously only obtained from biological sources, from inorganic reactants disproving the theory. The second law may be expressed in many specific ways, but the first formulation is credited to the French scientist Carnot in 1824. The first explicit statement of the first and second laws of thermodynamics was probably by Clausius in 1850.
Evolution Living organisms are highly complex and ordered = low entropy but create disorder = high entropy ΔSenergy= high CO2 + H2O Simple mixture of proteins ΔSchick= low ΔSegg= moderate Net ΔE = 0 Net ΔS = positive ΔG = -ve
Evolution Living organisms are highly complex and ordered = low entropy but create disorder = high entropy CO2 + H2O ΔSenergy= high Simple mixture of proteins ΔSchick= low ΔSegg= moderate Net ΔE = 0 Net ΔS = positive ΔG = -ve
Evolution = low E high S = higher E lower S more disorder – higher ΔS
Evolution ΔG is negative but it doesn’t say how fast!
EvolutionEvolution of the Universe Entropy increasesLife catalyses the rate of increase in entropy in the Universe!