BIOL 1441 1st Edition Exam 1 Study Guide Lectures 1 30 Ch 2 Electron proton neutron molecule compound o Electron subatomic particle with negative charge o Proton subatomic particle with positive charge o Neutron subatomic particle with neutral charge make up nucleus w protons o Molecule 2 or more atoms held together by a covalent bond o Compound substance consisting of 2 or more different elements combined in a fixed ratio Atomic number atomic weight cation anion o Atomic of protons equal to of electrons o Atomic weight atomic mass neutrons protons o Cation atom that loses an electron has positive charge o Anion atom that gains electron has negative charge Concept electrons and potential energy o The further away electrons are from the nucleus more potential energy the possess Hydrogen ionic covalent bonds polar nonpolar o Hydrogen bond hydrogen atom covalently bonded to one electronegative atom is attracted to another electronegative atom o Ionic bond attraction between oppositely charged molecules or atoms o Covalent bond sharing of electrons to fill valence shells Nonpolar electrons are shared equally no charge Polar electrons NOT shared equally charged Bonding capacity electronegativity o Bonding capacity the of covalent bonds the atom can form o Electronegativity attraction of an atom for the electrons in a covalent bond The more electronegative an atom the more strongly it pulls shared electrons to itself Electron configuration o The distribution of electrons in atom s electron shells that determine its chemical behavior Ch 3 Water Mole molar mass molecular weight molarity o Mole o Molar mass mass of 1 mol of a substance grams o Molecular weight ass of 1 molecule daltons o Molarity of moles of solute per liter of solution No molarity problems understand the concept behind it o 4 properties of water hydrogen bonding o cohesion binds a substance together H2O molecules attracted to each other H bonds Contributes to transport of H2O and dissolved nutrients against gravity in plants o moderation of temperature can absorb or release large amounts of heat with only a slight change in its own temp heat bank heat total amount of kinetic energy temperature average kinetic energy water has a high specific heat amount of heat must be absorbed or lost to change temp because of hydrogen bonds heat absorbed break H bonds heat released forms H bonds stabilizes ocean temp o expansion upon freezing water is less dense as a solid ice than a liquid water expands instead of contracting below 4 degrees Celsius b c hydrogen bonding water Is densest at 4 C freezing molecules are no longer moving vigorously enough to break H bonds ice floats water below is warmer insulated o versatility as a solvent solvent dissolving agent water solute substance that is dissolved salt aqueous solution water is solvent compound doesn t have to be ionic to be dissolved hydrophilic any substance with attraction to water charged ionic polar substances charged molecules attracted to charged molecules hydrophobic nonionic nonpolar substances repel water uncharged molecules attracted to uncharged molecules pH yes math problems o pH concentration of H ions in a solution acid solute that donates H low pH base reduces H high pH o pH negative logarithm base 10 of the hydrogen ion concentration Buffers o Keep pH relatively constant minimize change in H and OHo blood buffers keep blood at pH 7 4 o accepts H when they are in excess or donates H when there isn t enough Ch 4 Functional Groups Isomers structural geometric enantiomers o Isomer compounds with same molecular formula but different structures and properties Structural have different covalent arrangements of their atoms or location of double bond Geometric have same covalent arrangements but differ in spatial arrangements inflexibility of double bonds Cis isomer 2 Xs are on the same side Trans isomer 2 Xs are on opposite sides Enantiomers isomers that are mirror images of eachother Asymmetric carbon attached to 4 different atoms Medications one can be helpful other can be harmful Functional groups identify basic properties o Functional group chemical groups that affect molecular function Hydroxyl group OH Name alcohols ending in ol Polar result of electronegative oxygen atom drawing electrons toward itself attracts water molecules Carbonyl group CO Names o Ketone group within carbon skeleton o Aldehyde group at the end of carbon skeleton May be structural isomers with different properties found in sugars Carboxyl group COOH Name carboxylic acids Acidic properties source of H Amino group NH2 Name amines Acts as a base can pick up H from surrounding solution Sulfhydryl group SH Name thiols 2 sulfhydryl groups can interact to help stabilize protein structure Phosphate group OPO32 Name organic phosphates Makes the molecule an anion negative charge potential to react with H2O to release energy Methyl group CH3 Name methylated compounds Affects expression of genes shape can change function ONLY NON REACTIVE Ch 5 4 Classes Biological Molecules Dehydration condensation rxn Dehydration condensation lose a H2O molecule to build polymer Hydrolysis add a H2O molecule to break down polymer 4 major biological molecules Functions Basic properties Structure identify Bonds Carbohydrates sugars Monomer monosaccharide simple sugars Glucose most common monosaccharide Energy for cells Monosaccharides are classified by Location of carbonyl group carbons in carbon skeleton Disaccharides 2 monosaccharides joined by covalent bond by dehydration Storage polysaccharides Plants starch Animals glycogen Structural polysaccharides Plants cellulose Animals chitin Lipids DON T form polymers Hydrophobic 3 types fats phospholipids steroids fats not polymers energy storage large molecules made by dehydration rxns made from glycerol fatty acids fatty acid carboxyl group attached to long carbon skeleton 3 fatty acids glycerol triglyceride formed by ester linkage bond btwn hydroxyl and carboxyl group saturated fatty acid max hydrogen atoms and NO double bonds solid at room temp unsaturated fatty acid 1 or more double bonds KINK IN TAIL THAT KEEPS IT FROM PACKING TOO TIGHTLY liquid at room temp phospholipids 2 fatty acids phosphate group glycerol phosphate group hydrophilic head fatty acids hydrophobic tails make bilayer plasma membrane structure steroids carbon skeleton consisting of 4 fused rings CHOLESTEROL precursor to sex hormones Proteins Monomer amino acid Polymer polypeptides chains of amino acids