MCB 450 EXAM 1 [2026] UPDATED ACTUAL Exam |
Question and Answer | VERIFIED ANSWERS &
EXAM REVIEW
• What property of water allows it to dissolve ionic compounds? -✓✓ Its polarity
stabilizes separated ions through hydration shells
• What is the biological significance of hydrogen bonding in water? -✓✓ It
contributes to protein folding DNA stability and high heat capacity
• Rank the following interactions from strongest to weakest: hydrogen bonds van
der Waals interactions covalent bonds ionic interactions -✓✓ Covalent > Ionic >
Hydrogen Bond > Van der Waals
• Why are hydrophobic interactions considered entropy-driven? -✓✓ Clustering
hydrophobic molecules releases ordered water molecules increasing system
entropy
• What is the major force driving membrane formation? -✓✓ The hydrophobic
effect
• Define a Brønsted-Lowry acid -✓✓ A proton donor
• Define a Brønsted-Lowry base -✓✓ A proton acceptor
• What happens to a weak acid when the pH increases above its pKa? -✓✓ It
becomes increasingly deprotonated
, • What is the relationship between pH and proton concentration? -✓✓ pH = -
log[H⁺]
• If [H⁺] increases tenfold how does pH change? -✓✓ It decreases by 1 unit
• What does pKa represent? -✓✓ The pH at which half of the acid is protonated
and half is deprotonated
• At what pH is buffering most effective? -✓✓ At pH = pKa
• Using Henderson-Hasselbalch what is the ratio of A⁻ to HA when pH = pKa + 1? -
✓✓ 10:1
• What is the ratio of A⁻ to HA when pH = pKa - 1? -✓✓ 1:10
• Why are biological buffers important? -✓✓ They resist sudden pH changes that
could alter protein function
• What occurs at the half-equivalence point of a titration? -✓✓ pH = pKa
• What occurs at the equivalence point? -✓✓ Moles of acid equal moles of base
added
Question and Answer | VERIFIED ANSWERS &
EXAM REVIEW
• What property of water allows it to dissolve ionic compounds? -✓✓ Its polarity
stabilizes separated ions through hydration shells
• What is the biological significance of hydrogen bonding in water? -✓✓ It
contributes to protein folding DNA stability and high heat capacity
• Rank the following interactions from strongest to weakest: hydrogen bonds van
der Waals interactions covalent bonds ionic interactions -✓✓ Covalent > Ionic >
Hydrogen Bond > Van der Waals
• Why are hydrophobic interactions considered entropy-driven? -✓✓ Clustering
hydrophobic molecules releases ordered water molecules increasing system
entropy
• What is the major force driving membrane formation? -✓✓ The hydrophobic
effect
• Define a Brønsted-Lowry acid -✓✓ A proton donor
• Define a Brønsted-Lowry base -✓✓ A proton acceptor
• What happens to a weak acid when the pH increases above its pKa? -✓✓ It
becomes increasingly deprotonated
, • What is the relationship between pH and proton concentration? -✓✓ pH = -
log[H⁺]
• If [H⁺] increases tenfold how does pH change? -✓✓ It decreases by 1 unit
• What does pKa represent? -✓✓ The pH at which half of the acid is protonated
and half is deprotonated
• At what pH is buffering most effective? -✓✓ At pH = pKa
• Using Henderson-Hasselbalch what is the ratio of A⁻ to HA when pH = pKa + 1? -
✓✓ 10:1
• What is the ratio of A⁻ to HA when pH = pKa - 1? -✓✓ 1:10
• Why are biological buffers important? -✓✓ They resist sudden pH changes that
could alter protein function
• What occurs at the half-equivalence point of a titration? -✓✓ pH = pKa
• What occurs at the equivalence point? -✓✓ Moles of acid equal moles of base
added
