BIOL 102 Final: Official_Biology_102_Final_Course_Package_(2012).pdf

• School: Queen's University
• Department: Biology
• Course: BIOL 102
• Professor: Wayne Snedden

Document Summary

Atoms! (cid:1) atoms!consist!of!electrons,!protons,!and!neutrons: electrons!are!found!around!the!nucleus!and!carry!a!negative!charge, protons!and!neutrons!exist!within!the!nucleus!and!have!much!more!mass!than!electrons! (cid:1) protons!carry!a!positive!charge! (cid:1) neutrons!have!no!charge! (cid:1) atoms!are!mostly!empty!space, you!can!think!of!electrons,!protons,!and!neutrons!as!marbles!in!football!fields! Electrons! (cid:1) electrons!travel!within!regions!surrounding!the!nucleus!called!orbitals: s!orbitals!are!spherical, p!orbitals!are!propeller!shaped! (cid:1) each!orbital!can!only!hold!2!electrons! (cid:1) valence!electrons!are!the!unpaired!electrons!in!the!outermost!shell! (the!furthest!layer!of! orbitals), these!are!the!most!likely!electrons!to!be!involved!in!chemical!reactions! (rxns)! (cid:1) the!further!away!an!electron!is!from!the!nucleus,!the!more!potential!energy!it!has! Atomic!mass! (cid:1) mass!is!a!quantity!of!matter! (cid:1) weight!is!the!gravitational!pull!on!a!given!mass: therefore!depending!on!the!strength!of!the!gravitational!pull,!the!weight!of!an!object! can!change!even!though!its!mass!remains!the!same! (cid:1) a!mass!of!154!pounds!weighs!25!pounds!on!the!moon!but!21!trillion!pounds!on! a!neutron!star! (cid:1) atomic!mass!is!defined!as!the!total!number!of!protons!and!neutrons!in!an!atom! (cid:1) daltons!are!equal!to!1/12th!the!mass!of!a!carbon!atom, measured!in!daltons!(d)!or!atomic!mass!units! (amus), carbon!has!an!atomic!mass!of!12!d, the!most!common!form!of!carbon! (12c)!also!has!6!protons!and!6!neutrons! (cid:1) therefore!the!mass!of!one!proton!or!one!neutron!is!1!d! (cid:1) protons!and!neutron!are!about!equal!in!mass! (about!1800!times!greater!than!an!electron)! (cid:1) one!mole!(mol)!of!an!element! Bio!102! (cid:1) many!different!uses!in!biology: also!tells!you!that!isotopes!atomic!mass, biological!processes!within!organisms!rarely!use!isotopes! (cid:1) some!enzymes!can!recognize!them,!but!not!many, mostly!used!in!technical!applications! (cid:1) eg. !tissue!imaging,!tracking!metabolites,!dna!gels,!etc. Honc! (cid:1) honc!=!hydrogen,!oxygen,!nitrogen,!carbon! (cid:1) typically!make!up!about!95%!of!the!atoms!in!living!organisms: h!&!o!occur!primarily!in!water, n!found!in!proteins/nucleic!acids,!c!is!the!building!block!of!all!living!matter! Mineral!and!trace!elements! (cid:1) mineral!elements!constitute!less!than!1%! (cid:1) trace!elements!less!than!0. 01%! (cid:1) both!are!essential!for!normal!growth!and!function: think!of!iron!in!hemoglobin! Molecules!and!compounds! (cid:1) molecules!are!2!or!more!atoms!bonded!together:!o2! (cid:1) compounds!are!composed!of!2!or!more!elements:!h2o,!co2! (cid:1) molecular!formula!contains!chemical!symbols!of!elements!found!in!a!molecule: subscript!indicates!how!many!of!each!atom!are!present:!c6h12o6! Octet!rule! (cid:1) atoms!stable!when!their!outer!shell! (valence!shell)!is!full: for!many!atoms,!the!outer!shell!fills!with!8!electrons! (cid:1) one!exception!is!hydrogen,!which!fills!its!outer!shell!with!2!electrons! (cid:1) a!full!valence!shell! (with!8!or!2!electrons)!is!called!a!noble!gas!configuration! Covalent!bonds! (cid:1) covalent!bonds!occur!when!atoms!share!a!pair!of!electrons: occurs!between!atoms!whose!outer!electron!shells!are!not!full! (cid:1) covalent!bonds!are!often!the!strongest!of!all!chemical!bonds,!because!the!shared!electrons! behave!as!if!they!belong!to!each!atom! (cid:1) can!share:, 1!pair!of!electrons! Polar!covalent!bonds! (cid:1) polar!covalent!bonds!are!a!type!of!covalent!bonds!where!the!electrons!are!shared!unequally: this!means!that!the!electrons!are!closer!to!the!nucleus!of!one!atom!most!of!the!time, since!electrons!are!negative!this!makes!that!atom! (or!region!that!atom!occupies!in!the! molecule)!more!negative!and!the!atom! (or!region)!where!the!electron!is!not!more! positive! (cid:1) this!unequal!sharing!is!governed!by!the!electronegativity!of!the!atoms, (cid:20)(cid:34)(cid:35)(cid:45)(cid:1)(cid:35)(cid:45)(cid:1)(cid:41)(cid:32)(cid:46)(cid:31)(cid:40)(cid:1)(cid:45)(cid:34)(cid:41)(cid:49)(cid:40)(cid:1)(cid:27)(cid:45)(cid:1)(cid:58)+!(cid:69)(cid:45)(cid:38)(cid:35)(cid:33)(cid:34)(cid:46)(cid:38)(cid:51)(cid:1)(cid:42)(cid:41)(cid:45)(cid:35)(cid:46)(cid:35)(cid:48)(cid:31)(cid:70)(cid:1)(cid:41)(cid:44)(cid:1)(cid:58)*! (slightly!negative)!in!diagrams, (cid:20)(cid:34)(cid:31)(cid:1)(cid:39)(cid:41)(cid:44)(cid:31)(cid:1)(cid:31)(cid:38)(cid:31)(cid:29)(cid:46)(cid:44)(cid:41)(cid:40)(cid:31)(cid:33)(cid:27)(cid:46)(cid:35)(cid:48)(cid:31)(cid:1)(cid:46)(cid:34)(cid:31)(cid:1)(cid:27)(cid:46)(cid:41)(cid:39)(cid:1)(cid:35)(cid:45)(cid:1)(cid:46)(cid:34)(cid:31)(cid:1)(cid:33)(cid:44)(cid:31)(cid:27)(cid:46)(cid:31)(cid:44)(cid:1)(cid:64)(cid:42)(cid:47)(cid:38)(cid:38)(cid:65)(cid:1)(cid:35)(cid:46)(cid:1)(cid:31)(cid:50)(cid:31)(cid:44)(cid:46)(cid:45)(cid:1)(cid:41)(cid:40)(cid:1)(cid:46)(cid:34)(cid:31)(cid:1)(cid:31)(cid:38)(cid:31)(cid:29)(cid:46)(cid:44)(cid:41)(cid:40)(cid:45)(cid:1)(cid:35)(cid:40)(cid:1)(cid:46)(cid:34)(cid:31)(cid:1) bond! Instead!they!involve!electrostatic!attraction! (cid:1) a!compound!that! (cid:34)(cid:27)(cid:45)(cid:1)(cid:27)(cid:1)(cid:44)(cid:31)(cid:33)(cid:35)(cid:41)(cid:40)(cid:1)(cid:69)(cid:41)(cid:44)(cid:1)(cid:27)(cid:46)(cid:41)(cid:39)(cid:70)(cid:1)(cid:46)(cid:34)(cid:27)(cid:46)(cid:1)(cid:35)(cid:45)(cid:1)(cid:58)* (cid:27)(cid:46)(cid:46)(cid:44)(cid:27)(cid:29)(cid:46)(cid:45)(cid:1)(cid:46)(cid:34)(cid:31)(cid:1)(cid:58)+!region!that!is! (cid:1) most!often!this!occurs!between!compounds,!like!two!molecules!of!h2o,!and!is!called! near!the!h!atom!in!another!compound! intermolecular!h!bonding! Chemical!reactions! (cid:1) occurs!when!one!or!more!substances!are!changed!into!other!substances! (cid:1) most!biological!chemical!reactions!share!many!properties: when!reactants!(initial!starting!materials)!are!changed!into!products! (end!result), all!require!a!source!of!energy, reactions!in!living!organisms!often!require!a!catalyst! (enzymes)! Hydrophobic:!water!fearing! (cid:1) does!not!readily!dissolve!in!water! (cid:1) nonpolar!molecules!like!lipids! (membranes)! (cid:1) hydrophobic!molecules!like!other!hydrophobic!molecules! Water,!not!just!a!solvent! (cid:1) water!has!many!critical!functions!in!living!organisms: participates!in!chemical!reactions! (cid:1) hydrolysis!or!dehydration, provides!force!or!support, remove!toxic!waste!components, evaporative!cooling! (cid:1)