BIOL 111 1st EditionExam 1 Study Guideo Types of biological inquiry Discovery science - Has been around for 2500 years- Aristotle looked at chick development (incubated eggs and looked at what the chicks looked like after they hatched) Hypothesis- Enough data to make an educated guess as to what will happen in the experiment- Hypothesis-“a tentative answer to a well-framed question” (testable, falsifiable, verifiable) - Scientific theory-very broad in scope compared to a hypothesis, which is very specifico Is bakced up by scientific evidenceo Can be modifed or rejectedo Leads to new hypotheses - Examples of Sceintific theoryo Supported Cell theory, atomic, evolutionary, chromosomalo Rejected 5 kingdom theory of biodiversity- Inductive and deductive reasoningo Deductive reasoning arrives at a specific conclusion based on generalizations. Inductive reasoning takes events and makes generalizations- Chemical bondso Covalent-the electrons in the valance shell are being shared Non-polar covalent-equal sharing of electrons between the two elements Polar covalent-unequal sharing of electrons between the two element (the electrons are more attracted to one element than the other) Polar covalent bonds and electronegativity- Electronegativity-property of an atom to have a greater attraction to electrons in a bondo Ionic-electrons are transferred from one atom to another due to electronegativity; creates ions The atoms created are now ions because they are charged Salts dissolve in water and there are weak attractions between + and – poleso Hydrogen bond/Van der Waals forces/interactions Weak intermolecular forces that involve attractions between + and – poles (ex. Hydrogen bonding) Hydrogen bond: weak chemical bond between a H atom and an electronegative atom (such as O, N, S, or P)- Bufferingo Since most living cells exist between pH 6.5-8.0o Buffering molecules in/around cells minimize changes in [H+] and [OH-] by accepting - Hydrocarbon-anything that contains hydrogen and carbon (can only be hydrocarbon)o Gasoline and oil are examples of hydrocarbons as they are combustible, have all covalent bonds and are hydrophobico Isomers: compounds with the same # of atoms but different arrangements, thus different properties (isotopes have the same number of protons) - Isomers vs. isotopeso Isomers: same # of atoms, different arrangementso Isotopes: same # of protons, different # of neutrons- Functional groupsName Structure PropertiesHydroxyl Polar because the oxygen is electronegativeHydrogen bonded to an oxygenCarbonyl Polar in sugarsCarbon double bonded to an oxygenCarboxyl Carbon double bonded to an oxygen and bonded to a hydroxyl groupPolar, acidic, in amino acids fatty acidsAcid due to a carboxyl group attached to the moleculeAmino Can form to an additional bond with hydrogen and will decrease the amount of free hydrogen’s in the solution, making them always basicSulfhydryl Found in a few amino acids, important to protein structure Phosphate Very polar, lots of negatively charged atoms, in nucleic acids ATP and phospholipidsMethyl Addition to DNA or other molecules affects function of that moleculeMade up of a carbon and 3 hydrogens -- MacromoleculesMolecule Function(s)Carbohydrates Store energy; can also be structural elements in a cellLipids Store energy; structural; hormones (signaling) Protiens Widely varied (table 5.1)Nucleic acids Instructions for building and reporduction- Microscopeso Light microscopes use light to shine on/through the specimen Can magnify from 1000-2000Xo Electron microscope can magnify much more and can be used to see viruses and bacteriao Two different types of cells Prokaryotes-bacteria and archaea, single cell organisms found in very extreme environments - Pro-before, karyote-nucleus- Components-DNA, do not have ANY membrane bound components Eukaryotes o Fluid mosaic model (early 1970s) Fluid—lipids Mosaic—protiens (integral and peripheral) Movement of phospholipids- Lateral movement-movement side to side which occurs approximately 107 times per second- Flip flop movement-switch places across the membrane which occurs once per month Cholesterol-at high temperature=decrease into fluidity, at low temperature=morefluidity (fluidity meter)o Functions of protiens Transport Enzyme activity Signal transduction Cell-to-cell recognition Intercellular joining Attachment to the cytoskeleton and extracellular membrane (ECM)- Cell membraneso Why is selective permeability important?o What is transported in/out of cells?o How is it transported? Hydrophobic or nonpolar?- O2, CO2, steroids Hydrophilic, polar or charged?- Water, protiens, saccharides, ions- Diffusiono Tendency for molecules ot spread out o Down concentration gradiento If across biological membrane via passive transport—no energy requireso Lab examples: potassium permanganate or starch/amylase- Osmosiso Diffusion of water o Down concentration gradient You have to think of what the concentration of the amount of free molecules there are Move from the high concentration of free molecules o Via passive transport—no energy requiredo Across a selectively permeable membrane- Aquaporin o Channel proteins specific for watero Allow fast diffusion through cell membraneo 1st reported 1992 o Discovery awarded 1003 Nobel Prize in chemistry- Related termso Tonicity—property of a solution in reference to a particular membrane Isotonic-not net movement or solutions have equal solute Hypertonic-solution has higher solute compared to other Hypotonic-solution has lower solute compared to other- Movement across membraneo Simple diffusion (passive transport) Direct movement across membrane Down concentration gradient Usually small, hydrophobic (CO2, O2, hydrocarbons) o Facilitated diffusion (passive transport) Transport protiens required Down concentration gradient Used for hydrophilic molecules (polar, ions,
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