This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: 1 Lecture 2: Lecture 2: Water, Water, Noncovalent Noncovalent Bonds, Bonds, Acids, Bases, Buffers Acids, Bases, Buffers BIOCHEMISTRY 100 Winter 2009 M. Ziegler Learning Objectives Learning Objectives 1. Terminology (explain or deFne; understand use of terms) : polar (molecule, group.), hydrophilic, hydrophobic, amphipathic (same as amphiphilic), micelle, bilayer, ion product of water, Bronsted acid, Bronsted base, strong acid, weak acid, conjugate acid-base pair, pH, pK a , titration curve, buffer 2. Explain why water is a polar molecule, and why polar and charged molecules are so soluble in water. 3. Give examples of hydrophilic, hydrophobic, and amphipathic molecules. 4. List 4 types of noncovalent interactions important in biomolecular structures and interactions, and brieFy explain each. 5. Explain what a hydrogen bond is, including what types of groups/atoms serve as hydrogen bond donors and as hydrogen bond acceptors. Be able to look at structures of biomolecules as we learn them (or learn to recognize them) throughout the course and identify hydrogen bond donors and hydrogen bond acceptors in those structures. 6. Explain the difference between a hydrogen bond donor and a Bronsted acid (a proton donor ). 7. BrieFy explain why water has a much higher melting point and a much higher boiling point than methane. 8. Explain how the [H + ] and [OH ] concentrations are related in aqueous solutions. Be able to mathematically interconvert [H + ] and pH with a calculator. Learning Objectives, continued Learning Objectives, continued 9. Explain the relationship between how weakly a proton (H + ) is bound in a weak acid (the tendency of the weak acid to donate its proton) and the K a for that acid, and the pK a for that acid. 10. State the Henderson-Hasselbalch Equation (relating the conjugate base/weak acid ratio to the pH of the solution and the pK a of the weak acid, which is a constant) and be able to use that equation (with a non-programmable calculator) to calculate any one of those 3 parameters if you are given the other two. 11. Be able to qualitatively explain the relationship of the 3 parameters without a calculator . or example, when the pH = the pK a of the weak acid, what is the ratio of the conjugate base/weak acid? If the pH of the solution is higher than the value of the pK a , is the base/acid ratio greater than or less than 1? If the pH of the solution is lower than the pK a , is the base/acid ratio greater than or less than 1? 12. What is the effective buffer range of a conjugate base/weak acid pair relative to the pK a of the weak acid? 13. What is the principal buffer inside cells , and what is its approximate pK a ? 14. Explain why the bicarbonate / carbonic acid buffer system works well in blood in spite of the fact that the blood pH is at the very edge of the effective buffer range of that base/acid pair. Why would hyperventilation raise the blood pH?...
View Full Document
- Spring '08