Advanced Cell Biology. Lecture 7 Alexey Shipunov Minot State University January 25, 2013 Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 1 / 43
Outline Questions and answers Structure Other nucleic acids Macromolecules in cells Cells and energy Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 2 / 43
Outline Questions and answers Structure Other nucleic acids Macromolecules in cells Cells and energy Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 2 / 43
Outline Questions and answers Structure Other nucleic acids Macromolecules in cells Cells and energy Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 2 / 43
Outline Questions and answers Structure Other nucleic acids Macromolecules in cells Cells and energy Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 2 / 43
Questions and answers Previous final question: the answer Write a sequence complementary to ATTGGAAGC Is it from DNA or RNA? Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 3 / 43
Questions and answers Previous final question: the answer Write a sequence complementary to ATTGGAAGC Is it from DNA or RNA? TAACCTTCG DNA Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 3 / 43
Questions and answers Disulfide bonds movie Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 4 / 43
Structure Structure Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 5 / 43
Structure Hydrogen bonds in complementary strands Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 6 / 43
Structure Double helix DNA form helical structure where phosphate and sugar form envelope and bases form a core Two grooves: major and minor Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 7 / 43
Structure DNA double helix Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 8 / 43
Structure DNA double helix from top Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 9 / 43
Structure Sequences, ends, abbreviations Since nucleotides are complementary, it is usually only one strand listed Each strand has 3 ( OH) and 5 ends (phosphate) Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 10 / 43
Structure 3 and 5 ends Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 11 / 43
Structure Abbreviations for nucleic acids components Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 12 / 43
Structure Abbreviations for nucleotide sequences Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 13 / 43
Structure Nucleotides and UV light Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 14 / 43
Other nucleic acids Other nucleic acids Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 15 / 43
Other nucleic acids ATP ATP (adenosine-triphosphate) is coenzyme (ferment helper), derivative of ribose, adenine and three phosphoric acids Contain two highly energetic bonds Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 16 / 43
Other nucleic acids ATP Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 17 / 43
Other nucleic acids ATP movie ATP movie Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 18 / 43
Other nucleic acids NADP NADP, nicotinamide adenine dinucleotide phosphate is a coenzyme, derivative of adenine Typically, used as hydrogen carrier Has a medical name vitamin B 3 Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 19 / 43
Other nucleic acids NADPH Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 20 / 43
Other nucleic acids Other nucleotide coenzymes FAD, flavin adenine dinucleotide, vitamin B 2 CoA, coenzyme A, vitamin B 5 Both are extremely important for cell respiration Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 21 / 43
Other nucleic acids FAD Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 22 / 43
Other nucleic acids CoA Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 23 / 43
Macromolecules in cells Most frequent macromolecules Polymer molecules generate most of cell dry weight (30% of total weight) Proteins are 15%, nucleic acids 7%, lipids and polysaccharides 2% each Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 24 / 43
Macromolecules in cells Noncovalent bonds, conformations and binding Non-covalent bonds are responsible from shaping of macromolecules Almost every macromolecule has different shaping variants conformations Intermolecular binding is also due to noncovalent bonds Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 25 / 43
Macromolecules in cells Types of noncovalent bonds Hydrophobic forces Van der Waals attractions: due to fluctuation of electric charges Electrostatic, including hydrogen Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 26 / 43
Macromolecules in cells Binding with noncovalent (electrostatic) bonds Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 27 / 43
Cells and energy Metabolism Metabolism is the sum of all chemical reactions in living organism Catabolism is the part of metabolism responsible for degrading complex molecules Anabolism is the opposite part Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 28 / 43
Cells and energy Metabolism Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 29 / 43
Cells and energy Second law of thermodynamics 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. Simplistic definition: In isolated system, disorder is always increasing To revert initial order, energy should be spent Generally speaking, entropy is a measure of disorder (better measure of randomness) In strict sense, entropy is ds = δq T, where Q is amount of heat and T absolute temperature (constant) Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 30 / 43
Cells and energy Entropy Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 31 / 43
Cells and energy Triumph of entropy: post-apocalyptic world Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 32 / 43
Cells and energy Entropy explained: energy tube Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 33 / 43
Cells and energy Different forms of energy Mechanical energy: potential and kinetic Heat energy Electromagnetic energy All forms are inconvertible; and first law of thermodynamics says that energy never disappears, it only changes its form Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 34 / 43
Cells and energy Photosynthesis The way of transforming light energy to energy of chemical bonds The schematic description is: light energy + CO 2 + H 2 O sugars + O 2 + heat energy Part of anabolism Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 35 / 43
Cells and energy Cellular respiration Almost opposite process Schematic description: sugars + O 2 CO 2 + H 2 O + chemical energy (ATP) Part of catabolism Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 36 / 43
Cells and energy Oxidation and electron transfer Cellular respiration is based on oxidation, taking electrons off Converse reaction is reduction; together they are redox reactions For organic molecules, typical oxidation sequence is: carbohydrates alcohols aldehydes organic acids CO 2 Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 37 / 43
Cells and energy Enzymes and energy of activation Most of processes need the energy of activation Enzymes could lower activation barriers Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 38 / 43
Energy of activation Cells and energy Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 39 / 43
Cells and energy Catalysis movie Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 40 / 43
Cells and energy Final question (3 points) Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 41 / 43
Cells and energy Final question (3 points) How are living organisms working against the second law of thermodynamics? Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 41 / 43
Cells and energy Summary The second law of thermodynamics is about increasing entropy All metabolic reactions need energy Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 42 / 43
For Further Reading Cells and energy 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. Shipunov (MSU) Advanced Cell Biology. Lecture 7 January 25, 2013 43 / 43