Credit to STEPHEN ESPOSITO 2011 BSC2010 Stroupe We start out with the simple stuff Just read through and refresh your brain The tougher material will appear later in the unit I ve bolded and italicized some important topics that are most likely to be mentioned on the test from these sections UNIT ONE LECTURE 1 I Themes A Biology is hierarchical 1 Emergent properties a the sum of the parts is greater than the parts sum b new characteristics come through complex interactions of components 2 Reductionism analyzing something by taking it apart 3 Systems Biology put the reduced elements in the context of a whole B Organisms and their environment interact 1 Matter and energy are the commodities of the interaction 2 Ecosystems are dynamic continuously productive a matter nutrients cycle b energy flows Credit to STEPHEN ESPOSITO 2011 BSC2010 Stroupe 3 Energy conversion a light goes into chemical bonds b chemical bonds go into kinetic energy C Structure and function are coupled across resolutions 1 organisms appendages organs cells organelles molecules D Cells are the basic unit of life that can perform the basic activities of life 1 cell is a membrane enclosed unit of life 2 prokaryotes single cell DNA no organelles 3 eukaryotes single and multicellular DNA in nucleus organelles cytoplasm E Heritable information is in the structure and sequence of the DNA 1 double stranded helix 2 each strand is a sequence of four building block nucleotides 3 The sequence of the nucleotide specifies the sequence of another biomolecule DNA RNA protein this is the Central Dogma 4 The whole collection of an organism s DNA is its genome 5 information is hierarchical genome chromosome dsDNA helix sequence of the base units triplet sequence of the bases arrangements of the atoms in the bases Credit to STEPHEN ESPOSITO 2011 BSC2010 Stroupe F Feedback mechanisms control interactions 1 systems are not static they are dynamic 2 negative feedback product inhibits a process 3 positive feedback end product speeds up process II Inquiry A Discovery v Hypothesis 1 Discovery based research is based on observation and description through recorded data quantitative or qualitative a Inductive reasoning then draws general conclusions from specific observations 2 Hypothesis driven research seeks to answer questions based on prior patterns a Deductive reasoning predicts outcomes 3 Scientific discourse Hypothesis v Theory a Hypothesis is a predicted answer to a well formed question that can only be falsified never proven b Theory is a broad statement that is supported by a large number of hypothesis and models A theory explains diverse observations and spawns testable hypothesis about the observable world Credit to STEPHEN ESPOSITO 2011 BSC2010 Stroupe LECTURE 2 I Elements and compounds A Matter 1 Element substance that cannot be broken down into other substances 2 Compound substance with two or more different elements in a fixed ratio 3 C O H N make up 96 mass of living matter 4 P S Ca K Na Cl Mg make up about 4 5 The rest trace elements are B Cr Co Cu F I Fe Mn Mo Se Si Sn V Zn II Elements have properties related to their atomic structure A Atoms smallest unit of an element B Three subatomic particles 1 neutrons neutral in nucleus 1 Dalton 1 AMU 1 7e 24 g 2 protons positive charge in nucleus 1 Dalton a number of protons uniquely defines an atom b equivalent to the atomic number c protons neutrons mass number in the nucleus 3 electrons negative charge in space around the nucleus small fraction of a Credit to STEPHEN ESPOSITO 2011 BSC2010 Stroupe Dalton negligible in a neutrally charged atom 4 isotopes equivalent elements with different numbers of neutrons 5 formalism for recording this information a Atomic number number of protons In the elemental ie neutral form this also equals the number of electrons this is obvious b Mass number protons neutrons approximate mass of the atom c If you change number of protons you change the element If you change neutrons you make it a different isotope Isotopes are unstable if they have too many neutrons C Energy levels of electrons the source of that element s reactivity 1 Energy the capacity to cause change a Potential energy energy because of position in a force field or structure configuration b Kinetic energy energy of motion 2 Energy in an atom comes from the relative position of the electrons to the protons in the nucleus a Two models for understanding the energetics of an atom 1 shells electrons live in discreet shells with a defined energy quanta that are like train tracks that tell the train where it can go Credit to STEPHEN ESPOSITO 2011 BSC2010 Stroupe a The further from the nucleus the more Potential Energy from its shell to the next coming back down 2 orbitals Each shell has a defined shape a 1s 2 sphere b 2s 2 2p 6 sphere dumbbell D The chemical properties of an atom are related to electron distribution 1 Build all elements across the periodic table because one knows that each orbital holds a specific number of electrons so you know the SHAPE of the atom in a compound 2 outermost electrons are the valence electrons and they reside in the valence shell so you know the REACTIVITY of the atom 3 electronegativity measures how strongly a nucleus attracts an electron 4 atomic radius measures how big an atom is III Bonding there are FOUR types A Covalent bonds directly share valence electrons between atoms 1 when electrons are shared evenly between two equivalent atoms the bond is non polar The electrons spend an equal amount of time with each nucleus 2 when electrons are not shared evenly between two atoms the bond is polar The electrons spend more time around the nucleus that is more electronegative Credit to STEPHEN ESPOSITO 2011 BSC2010 Stroupe B Ionic bonds are a through space bond between atoms of opposite charge 1 Ions form when two atoms have such different electronegativites that one atom completely strips the electrons from the other atom usually resulting in full valences of both a cation charge b anion charge C Hydrogen bonds are through space bonds that happen between complementary ends 1 nomenclature for polar bonds includes the and D Van der Waals interactions occur between two atoms that form non polar covalent of two polar bonds bonds with other atoms IV Chemical reactions A Chemical equilibrium the balance between reactants and products when the rate of the forward and reverse chemical reactions are the same B An endothermic aka endergonic reaction ABSORBS energy
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