BSC 2010 Test 1 Study Guide Lecture 1 New Properties Emerge at Each Level of Hierarchy o Life can be studied by level Ex Atom Molecule Biosphere o Study of Life can be organized at different levels of biological organizations Emergent Properties o Result from the arrangement and interactions of parts in a system o Methods to study Emergent Properties 1 Reductionism reducing a complex system to its simplest component Makes it Manageable Ex Understanding DNA Structure o Developed by Watson Crick and Franklin in 1954 2 Systems Biology viewing an entire system as a whole and how they function together Construct models for dynamic behavior of entire biological systems Cells o Definition Organism s basic structure and function unit o Lowest level of life o All cells have a membrane and use DNA for genetic information Components Required for Life o 1 Homeostasis ability to maintain internal environment o 2 Organization structurally composed of at least one cell o 3 Metabolism ability to transform energy o 4 Growth maintenance of a higher rate of anabolism building up than catabolism breaking down o 5 Adaption ability to change over time o 6 Response to Stimuli o 7 Reproduction ability to form new organisms Most important aspect of life Cell Types 2 o 1 Prokaryotic Simple Cells without nucleus and membrane covered organelles Ex Bacteria o 2 Eukaryotic Membrane enclosed organelles Ex Plants and animals Continuity of Life o Based on inheritable info in the form of DNA Chromosomes contain the majority of DNA and are found in the nucleus o DNA is the substance of genes and build proteins o Genes units of inheritance that transmit info that pass from parent to offspring Cells differentiate by using specific sections of the DNA Central Dogma of Modern Biology o DNA RNA Protein o o Transcription Translation Structure of DNA o Shape Double Helix o Nucleotides A T C G Vary arrangement to create new cells o 1 2 of DNA codes for proteins Biology study of life o Two Ways to Study 1 Discovery Science observe and describe aspects of the world and draw conclusions from inductive reasoning 2 Hypothesis Based Science from observations scientists propose hypotheses and if they are correct it can be tested to determine an outcome Lecture 2 Matter o Definition Anything that takes up space and has mass o Made of pure chemical elements Compounds combinations of 2 or more elements in a fixed ratio o Makes up all organisms Element o Definition substance that cannot be further broken down chemically o Essential Elements of Life Consists of 25 elements Carbon hydrogen nitrogen and oxygen make up 96 of all life o Most of remaining 4 is calcium phosphorus potassium and sulfur Trace Elements required in small amounts less than Elemental Properties 100 mg daily o Depend on atom structure All elements are made of atoms Atom smallest unit of matter that retains properties of elements Made of subatomic particles Mass Charge No Charge 1 Dalton 1 Dalton 0 Location Atomic Nucleus Atomic Nucleus Electron Cloud Particle Proton Neutron Electron Periodic Table Electronegativity 1st Shel l 2nd Shel 3rd Shel l l Hydrogen 1 H 3 Li 11 Na Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine 4 Be 12 m Mg 5 B 13 Al 6 C 14 Si 7 N 15 s P 8 O 16 Sulfur S 9 F 17 Cl Sodium Magnesiu Aluminum Silicon Phosphoru Chlorine 2 Helium He 10 Neon Ne 18 Argon Ar 2 Atomic Number He Element Symbol 4 00 Atomic Mass o First shell can hold a maximum of 2 electrons o Second o All elements in the first column have one electron in their valence and Third shells can each hold a maximum of eight electrons All elements in column two have two electrons in their valence Elements in column three have three electrons and so outer shell shell Isotopes on o Atoms of the same element with different numbers of neutrons o Radioactive Applications Carbon Dating Diagnosing Medical Disorders Tracing Atoms in Metabolic Processes Energy o Capacity to cause change Potential Energy energy due to location and structure o As shell level increases energy levels increase Due to electrons in higher shells having higher energy o Energy is lost emitted when electrons drop down in shells Energy is absorbed when electrons increase in shell level Electron Distribution o Chemical behavior of atoms are determined by how electrons are arranged in shells Illustrated by the periodic table o Valence Electrons e present in outer most shell valence shell Valence shell electrons react and determine the chemical behavior of an element Chemically Inert Full valence shell makes elements unreactive Electronegativity element s tendency to take electrons o Oxygen is the most electronegative element of life o Carbon is the best sharer of electrons The Ultimate Sharer Bond Types 2 o 1 Covalent Bond equal sharing of valence electrons 2 Types Nonpolar Covalent Bond completely equal sharing of electrons o Ex H2 CH4 Polar Covalent Bond unequal sharing of electrons resulting in partial positive and negative charges o Ex H2O The two hydrogen atoms have a partial positive charge and the oxygen has a partial negative charge because of its high electronegativity o Partial Charge more electronegative atom keeps more electrons around it Negative Charge o Nonpolar Harder to break Releases more energy Ex Hydrocarbon o Polar Easily broken bonds Releases less energy Ex Carbs division of electrons Ex HCl H Cl o 2 Ionic Bond forms ions charged particles due to the complete Lecture 3 Water o Appears to be unique to Earth Required for Life o Covers of Earth s surface o Makes up 60 70 of weight of all life o Regenerated and redistributed by the water cycle o Only molecule that exists naturally in all three states solid liquid gas Structure of Water o Chemical Formula H2O o Bond Angle 104 5o o Figure Hd Hd Od Forms of Water 3 o 1 Solid Ice Hydrogen bonds are stable Forms a Hexagonal Lattice More spacious than liquid form less dense Fragile and disorganized hydrogen bonds Bonds last a few trillionths of a second o 2 Liquid o 3 Gas Single molecules liberated by the addition of energy o Results from partial negative charge of oxygen and partial positive Hydrogen Bonding of Water charge of hydrogen Emergent Properties of Water o These properties make water ideal for life 5 1 Adhesion Cohesion and Surface Tension Cohesion phenomenon of hydrogen bonds holding water molecules together Adhesion phenomenon of hydrogen bonds of water holding onto something else o Ex Water holding onto the cell walls of a tree to climb to the
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