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 Cells systems 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 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 o DNA is the substance of genes and build proteins o Genes units of inheritance that transmit info that pass from parent to nucleus offspring Cells differentiate by using specific sections of the DNA Central Dogma of Modern Biology DNA RNA Protein o 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 Particle Proton Neutron Electron Periodic Table 1st Shell 2nd Shell 3rd Shell 1 Hydrogen H 3 Lithium Li 11 Sodium Na Trace Elements required in small amounts less than 100 Elemental Properties o Depend on atom structure mg daily All elements are made of atoms Atom smallest unit of matter that retains properties of elements Made of subatomic particles Mass 1 Dalton 1 Dalton 0 Charge No Charge Location Atomic Nucleus Atomic Nucleus Electron Cloud Electronegativity 4 Beryllium Be 12 Magnesium Mg 5 Boron B 13 Aluminum Al 6 Carbon C 14 Silicon Si 7 Nitrogen N 15 Phosphorus P 8 Oxygen O 16 Sulfur S 9 Fluorine F 17 Chlorine Cl 2 Helium He 10 Neon Ne 18 Argon Ar 2 cid 223 Atomic Number He cid 223 Element Symbol 4 00 cid 223 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 outer and Third shells can each hold a maximum of eight electrons shell shell Isotopes All elements in column two have two electrons in their valence Elements in column three have three electrons and so 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 Bond Types 2 The Ultimate Sharer 2 Types o 1 Covalent Bond equal sharing of valence electrons 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 o Polar Easily broken bonds Releases less energy Ex Carbs division of electrons o 2 Ionic Bond forms ions charged particles due to the complete 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 Ex Cl HCl H Lecture 3 Water 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 charge Hydrogen Bonding of Water 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
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