FBICH 410 1st Edition Lecture 2Outline of Last Lecture - Covalent Bonds- Noncovalent bonds- Water and the importance of Hydrogen bondsOutline of Current Lecture - Ka = ionized constant or weak acid in awatero -logKa=Pkao Smaller pka= stronger weak acido Larger Ka= stronger weak base- pH determined by both pka of conjugate acid/base pair and the conc of conjugate acid/base pair- pH= pka+ log[deprotanated/protonated] Henderson Hasselbacho charged form could be protonated or deprotonated - When pH=Pka [A-]=[HA]- When Ph<Pka, larger pka less likely to dissociate- When pH>Pka, smaller pka more likely to dissociate/more deprotonated- Titration Curves- adding strong base to weak acid and measuring change in Pho Graph pH v. amount of strong base addedo Inflection point [acid]=[base]These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.o Should be able to determine pka and which form will predominate (ie acid or base) as a certain spot on graph- Bio Systems Bufferedo Buffers- resist changes in PH as acid and base are addedo Titration curve near pka is buffero The greater the conc of weak acid and its conj base, the greater the buffer capaciteo Find good buffer by matching desired pH with matching pka of buffer- Major Bio Bufferso H2PO4-/H2PO42- The principle buffer in cells (pka=7)o H2CO3/HCO3- Important buffer in the blood CO2 +H20 H+ +HCO3- CO2=[HA] HCO3-=[A-]- Changes in Blood Chemistryo Breathing induced: CO2 +H20 H+ +HCO3- Hyperventilation result in increased blood pH. CO2 down so body pushes rxn to the left causing HCO3- to decrease. So pH increases because [H+] decreases---- respiratory alkalosis Hypoventilation results in decreased blood pH. Increase in CO2 combines with H20 to produce more[H+] so pH decreases--- respiratory acidosiso Metabolically induced Decreases in blood pH result increases breathing rate. pH decreases [H+]increases so H+ combines w HCO3- to produce more CO2—metabolic acidosis Increase in blood pH (very rare) decreases breathing rate pH increases or [H+] decreases. CO2 combines w H20—metabolic alkalosis- Thermodynamics, Kinetics, Equilibriumo Thermodyamics- are products possible (spontaneous v non) (favorable v. non)o Kinetics- expresses how fast process occurso Equilibrium- how far rxn will go State in which forward rxn=reverse rxn Conc of reactants and products remain constant over time but not equal dynamic process All chem rxn proceed until equilibrium reached Equilibrium level for a rxn is intrinsic to each specific rxn Le Chateliers- any stress placed on equilibrium system will cause the system to shift to minimize effect of stress Equilibrium constant keq= [Products]x/[Reactants]x- Change temp causes change in keq- Keq<1 more reactants - Keq>1 products
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