Biology 1101 Final Thursday April 24 10 00 11 45 am Hitchcock Hall Room 131 The Ohio State University Biology 1101 Dr Kristin Smock Semester Spring 2014 1 Biology 1101 Accumulative Study Guide Week 1 Biology is the study of life Life is o Atom molecule organelle tissue organ organ system organism population community ecosystem biosphere o Cell considered to be the smallest unit of life Every living thing requires energy which enables organisms to Build new structures Repair old structures Reproduce o Living things must maintain internal constancy Must maintain internal conditions through certain boundaries Homeostasis State of internal constancy Living things reproduce grow develop 2 o All living things come from other living things o DNA is copied and passed onto offspring The signature molecule of life Living things evolve environment o Why do some organisms seem perfectly suited to their o Examples hummingbird cheetah polar bear mimic octopus Blending adapting essential traits for survival Adaptation Characteristics that are inherited in which influence an organism s ability to survive and reproduce Population Group of individuals of the same species that occupy the same habitat and interact with one another Individuals that survive long enough to reproduce have acquired the most primitive adaptations to their current local environment Evolution Change in genetic makeup of a population over time Natural Selection Charles Darwin s Theory of Evolution is one mechanism of evolution How we study the natural world Steps to the Scientific Method 1 Make Observations 2 Ask Questions that are relatable testable How Why 3 Propose a hypothesis 4 Come up with a prediction o If hypothesis is true then we expect 5 Design a Controlled Experiment 3 o Experimental Design Variables Sample Size o Independent manipulated variable Graph bottom independent o Dependent response variable Graph side dependent o Standardized variables Control Treatment 6 Collect Data 7 Publish Results Interpret and analyze results Draw Conclusions Data able to be interpreted tested by fellow scientists Hypothesis vs Theory Hypothesis Tentative omen narrow explanation regarding the natural world Must be testable and falsifiable A well substantiated explanation of some aspect of the natural world A unifying explanation Ideas in which scientists are most certain Theory Pure substance that cannot be broken down by chemical Chemistry of Life Elements means Atom the smallest component of an element o Composed of subatomic particles Protons positive Neutrons neutral Electrons negative The Periodic Table of Elements 4 Atomic Number the of protons in the nucleus o All atoms of a given element have the same atomic number 5 o When protons electrons atom is neutral o When protons electrons atom is an ion ex Carbon Chemical Bonds link atoms Atoms bond through chemical bonds forces of attraction that hold atoms together o Molecule We refer to molecules using their molecular formula 2 or chemically bonded atoms o Ex water H2O Electrons determine bonding o Electrons move around the nucleus in energy shells Octet Rule shell valence shell atoms ions are most stable when they have 8 e in outer E o First energy shell only has room for 2 electrons o If the outer energy shell is full the atom is stable and will not react o If not atoms ions will lose gain or share electrons to fill their outer shell o This is the valence of chemical reactions Covalent bonds the sharing bond o To satisfy the octet rule some atoms will share electrons 6 Shared e travels around both nuclei Single double triple bonds represented by lines o Sharing isn t always equal Atoms omen have different electronegativity the ability to attract electrons Nonpolar covalent bond electronegativity ex H2 CH4 Polar covalent bond unequal sharing of e s both atoms have equal Ionic bond the stealing bond take an e from another o If the difference in electronegativity is great enough one atom will Ex Na and Cl form sodium chloride NaCl salt An ionic bond results from the electrical reaction between 2 negatively charged ions Hydrogen bonds bonds of attraction o A hydrogen bond is a weak force of attraction between two atoms or ions with opposite partial charges Ex water molecule o Opposite partial charges attract on adjacent molecules But they are weak Which brings us to water o Hydrogen bonds result in a property of water called 7 Cohesion water molecules stick together Results in high surface tension o Water in space Properties of Water o Polar substances dissolve in water Ex NaCl Sodium Chloride salt in water o Molecules of water surround each ion separate from one another o Substances that dissolve in water are hydrophilic water loving ex salt sugar ions o Substances that don t dissolve in water are hydrophobic water fearing ex oil fats Water s Reaction to Temperature o Ice floats When the temperature drops water molecules slow down and keep their H bonds longer Locks into a crystalline lattice with its neighbors Less molecules in a given space the density is now lower Week 2 Organic Molecules hydrogen o Organic molecules are compounds containing both carbon 8 o Many are macromolecules which are usually Polymers monomers linked together like a train chains created by linking subunits called Four Main Types 1 Carbohydrates 2 Lipids 3 Proteins 4 Nucleic Acids 1 Carbohydrates Simplest of the main organic molecules o Used as A source of energy Structural molecules o Consist of 2 main types Simple sugars Complex carbs o Glucose Formula C6H12O6 Primary fuel source Your body can use it or store it Animals store energy as glycogen 2 Lipids fats 9 o All lipids are insoluble in water o Rich in energy good for long term E storage Lots of C H bonds o Triglycerides o Saturated fats contain all the H s possible Single bonds connect all the carbons Solid at room temperature Degree of saturation is a measure of a fatty acid s H content Tend to be animal derived cheese butter have 1 double bond b t C s double bonds o Unsaturated fats produce kinks in chain Sites of unsaturation double bonds Liquid at room temperature Tend to be plant derived vegetable oil olive oil o Hydrogenation adding hydrogen 3 Proteins o Very diverse More functions in the cell than any Other type of molecule o A protein is a chain of amino acids Composed of several parts 10 20 amino acids o Fold into unique 3 D structures inside a cell o The protein s overall shape is what determines its overall function o Each protein s