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Advanced Cell Biology. Lecture 7 Advanced Cell Biology. Lecture 7 Advanced Cell Biology. Lecture 7 Alexey Shipunov Minot State University January 27, 2012 Advanced Cell Biology. Lecture 7 Outline Questions and answers Nucleic acids Structure Other nucleic acids Macromolecules in cells Cells and energy Advanced Cell Biology. Lecture 7 Outline Questions and answers Nucleic acids Structure Other nucleic acids Macromolecules in cells Cells and energy Advanced Cell Biology. Lecture 7 Outline Questions and answers Nucleic acids Structure Other nucleic acids Macromolecules in cells Cells and energy Advanced Cell Biology. Lecture 7 Outline Questions and answers Nucleic acids Structure Other nucleic acids Macromolecules in cells Cells and energy I TAACCTTCG I DNA Advanced Cell Biology. Lecture 7 Questions and answers Previous final question: the answer Write a sequence complementary to ATTGGAAGC Is it from DNA or RNA? Advanced Cell Biology. Lecture 7 Questions and answers Previous final question: the answer Write a sequence complementary to ATTGGAAGC Is it from DNA or RNA? I TAACCTTCG I DNA Advanced Cell Biology. Lecture 7 Nucleic acids Structure Nucleic acids Structure Advanced Cell Biology. Lecture 7 Nucleic acids Structure Hydrogen bonds in complementary strands Advanced Cell Biology. Lecture 7 Nucleic acids Structure Double helix I DNA form helical structure where phosphate and sugar form “envelope” and bases form a “core” I Two grooves: major and minor Advanced Cell Biology. Lecture 7 Nucleic acids Structure DNA double helix Advanced Cell Biology. Lecture 7 Nucleic acids Structure DNA double helix from top Advanced Cell Biology. Lecture 7 Nucleic acids Structure Sequences, ends, abbreviations I Since nucleotides are complementary, it is usually only one strand listed I Each strand has 3’ (–OH) and 5’ ends (phosphate) Advanced Cell Biology. Lecture 7 Nucleic acids Structure 3’ and 5’ ends Advanced Cell Biology. Lecture 7 Nucleic acids Structure Abbreviations for nucleic acids components Advanced Cell Biology. Lecture 7 Nucleic acids Structure Abbreviations for nucleotide sequences Advanced Cell Biology. Lecture 7 Nucleic acids Structure Nucleotides and UV light Advanced Cell Biology. Lecture 7 Nucleic acids Other nucleic acids Nucleic acids Other nucleic acids Advanced Cell Biology. Lecture 7 Nucleic acids Other nucleic acids ATP I ATP (adenosine-triphosphate) is coenzyme (ferment helper), derivative of ribose, adenine and three phosphoric acids I Contain two highly energetic bonds Advanced Cell Biology. Lecture 7 Nucleic acids Other nucleic acids ATP Advanced Cell Biology. Lecture 7 Nucleic acids Other nucleic acids ATP movie ATP movie Advanced Cell Biology. Lecture 7 Nucleic acids Other nucleic acids NADP I NADP, nicotinamide adenine dinucleotide phosphate is a coenzyme, derivative of adenine I Typically, used as hydrogen carrier I Has a medical name “vitamin B3” Advanced Cell Biology. Lecture 7 Nucleic acids Other nucleic acids NADPH Advanced Cell Biology. Lecture 7 Nucleic acids Other nucleic acids Other nucleotide coenzymes I FAD, flavin adenine dinucleotide, vitamin B2 I CoA, coenzyme A, vitamin B5 I Both are extremely important for cell respiration Advanced Cell Biology. Lecture 7 Nucleic acids Other nucleic acids FAD Advanced Cell Biology. Lecture 7 Nucleic acids Other nucleic acids CoA Advanced Cell Biology. Lecture 7 Macromolecules in cells Most frequent macromolecules I Polymer molecules generate most of cell dry weight (30% of total weight) I Proteins are 15%, nucleic acids 7%, lipids and polysaccharides 2% each Advanced Cell Biology. Lecture 7 Macromolecules in cells Noncovalent bonds, conformations and binding I Non-covalent bonds are responsible from shaping of macromolecules I Almost every macromolecule has different shaping variants—conformations I Intermolecular binding is also due to noncovalent bonds Advanced Cell Biology. Lecture 7 Macromolecules in cells Types of noncovalent bonds I Hydrophobic forces I Van der Waals attractions: due to fluctuation of electric charges I Electrostatic, including hydrogen Advanced Cell Biology. Lecture 7 Macromolecules in cells Binding with noncovalent (electrostatic) bonds Advanced Cell Biology. Lecture 7 Cells and energy Metabolism I Metabolism is the sum of all chemical reactions in living organism I Catabolism is the part of metabolism responsible for degrading complex molecules I Anabolism is the opposite part Advanced Cell Biology. Lecture 7 Cells and energy Metabolism Advanced Cell Biology. Lecture 7 Cells and energy Second law of thermodynamics I Thermodynamic definition (Rudolf Clausius): No process is possible whose sole result is the transfer of heat from a body of lower temperature to a body of higher temperature. I Simplistic definition: In isolated system, disorder is always increasing I To revert initial order, energy should be spent I Generally speaking, entropy is a measure of disorder (better—measure of randomness) δQ I In strict sense, entropy is dS = T , where Q is amount of heat and T —absolute temperature (constant) Advanced Cell Biology. Lecture 7 Cells and energy Entropy Advanced Cell Biology. Lecture 7 Cells and energy Triumph of entropy: “post-apocalyptic world” Advanced Cell Biology. Lecture 7 Cells and energy Entropy explained: energy tube Advanced Cell Biology. Lecture 7 Cells and energy Different forms of energy I Mechanical energy: potential and kinetic I Heat energy I Electromagnetic energy I All forms are inconvertible; and first law of thermodynamics says that energy never disappears, it only changes its form Advanced Cell Biology. Lecture 7 Cells and energy Photosynthesis I The way of transforming light energy to energy of chemical bonds I The schematic description is: light energy + CO2 + H2O ! sugars + O2 + heat energy I Part of anabolism Advanced Cell Biology. Lecture 7 Cells and energy Cellular respiration I Almost opposite process I Schematic description: sugars + O2 ! CO2 + H2O + chemical energy (ATP) I Part of catabolism Advanced Cell Biology. Lecture 7 Cells and energy Oxidation and electron transfer I Cellular respiration is based on oxidation, taking electrons off I Converse reaction is reduction; together they are redox reactions I For organic molecules, typical oxidation sequence is: carbohydrates ! alcohols ! aldehydes ! organic acids ! CO2 Advanced Cell Biology. Lecture 7 Cells and energy Enzymes and energy of activation I Most of processes need the energy of activation I Enzymes could lower activation barriers Advanced Cell Biology. Lecture 7 Cells and energy Energy of activation Advanced Cell Biology. Lecture 7 Cells and energy Catalysis movie Advanced Cell Biology. Lecture 7 Cells and energy Enzyme terminology: catalysis and substrate I Enzyme binds with substrate, I then catalyze conversion of substrate into product, I and returns untouched to the initial state Advanced Cell Biology. Lecture 7 Cells and energy Catalysis terms Advanced Cell Biology. Lecture 7 Cells and energy Enzyme performance I Two numbers are using for measuring enzyme performance: Vmax and KM I Vmax is maximal available reaction rate I KM is the concentration of substrate when the rate is Vmax=2 Advanced Cell Biology. Lecture 7 Cells and energy Enzyme performance How living organisms are working against the second law of thermodynamics? Advanced Cell Biology. Lecture 7 Cells and energy Final question (3 points) Advanced Cell Biology. Lecture 7 Cells and energy Final question (3 points) How living organisms are working against the second law of thermodynamics? Advanced Cell Biology. Lecture 7 Cells and energy Summary I The second law of thermodynamics is about increasing entropy I All metabolic reactions need energy Advanced Cell Biology. Lecture 7 Cells and energy For Further Reading A. Shipunov. Advanced Cell Biology [Electronic resource]. 2011—onwards. Mode of access: http: //ashipunov.info/shipunov/school/biol_250 B. Alberts et al. Essential Cell Biology. 3rd edition. Garland Science, 2009. Chapter 2, Chapter 3: 58–100..
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