Question 1

Which of the following classes of compounds is hydrophobic?

Accepted Answer

A)  Table Salt 
B)  Cholesterol 
C)  Phosphate esters 
D)  Cholesterol and phosphate esters. 
E)  All of these are hydrophobic. 
A)  Table Salt 
B)  Cholesterol 
C)  Phosphate esters 
D)  Cholesterol and phosphate esters. 
E)  All of these are hydrophobic.

Question 2

The main blood buffer system is

Accepted Answer

A)  H2CO3/HCO3− 
B)  HCO3−/CO32− 
C)  H2CO3/CO32− 
D)  none of the above 
A)  H2CO3/HCO3− 
B)  HCO3−/CO32− 
C)  H2CO3/CO32− 
D)  none of the above

Question 3

Molecules which contain both hydrophilic and hydrophobic regions are:

Accepted Answer

A)  Amphipathic 
B)  Amphiphilic 
C)  Able to form micelles 
D)  Both amphipathic and amphiphilic 
E)  All of these 
A)  Amphipathic 
B)  Amphiphilic 
C)  Able to form micelles 
D)  Both amphipathic and amphiphilic 
E)  All of these

Question 4

A London dispersion force is another name for a(n)

Accepted Answer

A)  induced dipole - induced dipole bond 
B)  ionic bond 
C)  covalent bond 
D)  non-polar bond 
A)  induced dipole - induced dipole bond 
B)  ionic bond 
C)  covalent bond 
D)  non-polar bond

Question 5

In a hydrogen bond

Accepted Answer

A)  three atoms lie in a straight line 
B)  there is stronger bonding than in a covalent bond 
C)  unpaired electrons play no role 
D)  none of the above 
A)  three atoms lie in a straight line 
B)  there is stronger bonding than in a covalent bond 
C)  unpaired electrons play no role 
D)  none of the above

Question 6

Which of the following characteristics makes for a good hydrogen bond acceptor?

Accepted Answer

A)  a high electronegativity 
B)  a nonbonding pair of electrons 
C)  both of these 
D)  neither of these 
A)  a high electronegativity 
B)  a nonbonding pair of electrons 
C)  both of these 
D)  neither of these

Question 7

The pOH a solution of 0.04 M HCl is:

Accepted Answer

A)  1.4 
B)  10 
C)  12.6 
D)  13.6 
E)  The pOH cannot be determined 
A)  1.4 
B)  10 
C)  12.6 
D)  13.6 
E)  The pOH cannot be determined

Question 8

Buffering capacity refers to

Accepted Answer

A)  the effectiveness of commercial antacids 
B)  the extent to which a buffer solution can counteract the effect of added acid or base 
C)  the pH of a buffer solution 
D)  the molecular weight of the substance used as a buffer 
A)  the effectiveness of commercial antacids 
B)  the extent to which a buffer solution can counteract the effect of added acid or base 
C)  the pH of a buffer solution 
D)  the molecular weight of the substance used as a buffer

Question 9

Buffers work to maintain pH because

Accepted Answer

A)  they obey LeChatlier's principle 
B)  weak acids cannot change the pH of a solution 
C)  weak bases added to strong bases neutralize each other 
D)  they destroy the hydrogen ion that is added 
A)  they obey LeChatlier's principle 
B)  weak acids cannot change the pH of a solution 
C)  weak bases added to strong bases neutralize each other 
D)  they destroy the hydrogen ion that is added

Question 10

If the pH of 1 liter of a 1.0 M carbonate buffer is 7.0, what is the molar ratio of H2CO3 to HCO3−? (pK = 6.37)

Accepted Answer

A)  0.234 
B)  4.27 
C)  6.37 
D)  7.00 
E)  10.20 
A)  0.234 
B)  4.27 
C)  6.37 
D)  7.00 
E)  10.20

Question 11

What is the pH of a solution with [H+] = 10 mM?

Accepted Answer

A)  10 
B)  1 
C)  2 
D)  −2 
A)  10 
B)  1 
C)  2 
D)  −2

Question 12

Which of the following molecules has polar bonds but is itself not polar?

Accepted Answer

A)  NH3 
B)  CO2 
C)  CH4 
D)  H2O 
A)  NH3 
B)  CO2 
C)  CH4 
D)  H2O

Question 13

How does the strength of hydrogen bonds compare with covalent bonds?

Accepted Answer

A)  Hydrogen bonds are much stronger than covalent bonds. 
B)  Hydrogen bonds are much weaker than covalent bonds. 
C)  Hydrogen bonds and covalent bonds have similar strengths. 
D)  The question cannot be answered without knowing which covalent bonds are being referred to 
A)  Hydrogen bonds are much stronger than covalent bonds. 
B)  Hydrogen bonds are much weaker than covalent bonds. 
C)  Hydrogen bonds and covalent bonds have similar strengths. 
D)  The question cannot be answered without knowing which covalent bonds are being referred to

Question 14

An HCl solution has a pH = 3. If you dilute 10 mL of the solution to 1000mL, the final pH will be:

Accepted Answer

A)  1.0 
B)  2.0 
C)  The pH does not change. 
D)  4.0 
E)  5.0 
A)  1.0 
B)  2.0 
C)  The pH does not change. 
D)  4.0 
E)  5.0

Question 15

Which has the greater Ka, a weak acid or a strong acid?

Accepted Answer

A)  A weak acid. 
B)  A strong acid 
C)  They should dissociate about the same. 
D)  It's impossible to predict. 
A)  A weak acid. 
B)  A strong acid 
C)  They should dissociate about the same. 
D)  It's impossible to predict.

Question 16

Which of the following compounds is most likely to form a micelle?

Accepted Answer

A)  Acetic acid. 
B)  Glucose. 
C)  Glycerol. 
D)  Sodium palmitate. 
E)  Sodium phosphate. 
A)  Acetic acid. 
B)  Glucose. 
C)  Glycerol. 
D)  Sodium palmitate. 
E)  Sodium phosphate.

Question 17

Exhibit 2A The structure of ATP with various groups labeled.Group III is the entire phosphate group.
  
-Refer to Exhibit 2A. Which of the functional groups cannot function as a hydrogen donor to water?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
E)  All can donate a hydrogen to water. 
A)  I 
B)  II 
C)  III 
D)  IV 
E)  All can donate a hydrogen to water.

Question 18

The main intracellular buffer system is

Accepted Answer

A)  H3PO4/H2PO4− 
B)  H2PO4−/ HPO42− 
C)  HPO42−/PO43− 
D)  H3PO4/PO43− 
A)  H3PO4/H2PO4− 
B)  H2PO4−/ HPO42− 
C)  HPO42−/PO43− 
D)  H3PO4/PO43−

Question 19

Exhibit 2B
Contains information on the pK's of some common buffers.
$\begin{array}{llrc}
\text { Buffer } & \mathbf{p K} 1 & \mathbf{p K 2} & \mathbf{p K} 3 \
\hline \text { Acetate } & 4.75 & & \
\text { Ammonia } & 9.25 & & \
\text { Carbonic acid } & 6.37 & 10.20 & \
\text { Citric acid } & 3.09 & 4.75 & 5.41 \
\text { Formic Acid } & 3.75 & & \
\text { Phosphoric acid } & 2.14 & 7.20 & 12.4 \
\text { Pyruvic acid } & 2.50 & & \
\text { Tris } & 8.3 & &
\end{array}$

-Refer to Exhibit 2B. A phosphate buffer would work well at this pH:

Accepted Answer

A)  5.0 
B)  7.0 
C)  8.0 
D)  10.0 
E)  7.0 and 8.0 
A)  5.0 
B)  7.0 
C)  8.0 
D)  10.0 
E)  7.0 and 8.0

Question 20

Which of the following is a correct listing of electronegativity values, from low to high?

Accepted Answer

A)  C, H, O, N 
B)  N, H, O, C 
C)  H, C, N, O 
D)  H, C, O, N 
A)  C, H, O, N 
B)  N, H, O, C 
C)  H, C, N, O 
D)  H, C, O, N

Exam 2: Water: the Solvent for Biochemical Reactions

Which of the following classes of compounds is hydrophobic?

The main blood buffer system is

Molecules which contain both hydrophilic and hydrophobic regions are:

A London dispersion force is another name for a(n)

In a hydrogen bond

Which of the following characteristics makes for a good hydrogen bond acceptor?

The pOH a solution of 0.04 M HCl is:

Buffering capacity refers to

Buffers work to maintain pH because

If the pH of 1 liter of a 1.0 M carbonate buffer is 7.0, what is the molar ratio of H2CO3 to HCO3−? (pK = 6.37)

What is the pH of a solution with [H+] = 10 mM?

Which of the following molecules has polar bonds but is itself not polar?

How does the strength of hydrogen bonds compare with covalent bonds?

An HCl solution has a pH = 3. If you dilute 10 mL of the solution to 1000mL, the final pH will be:

Which has the greater Ka, a weak acid or a strong acid?

Which of the following compounds is most likely to form a micelle?

Exhibit 2A The structure of ATP with various groups labeled.Group III is the entire phosphate group. -Refer to Exhibit 2A. Which of the functional groups cannot function as a hydrogen donor to water?

The main intracellular buffer system is

Which of the following is a correct listing of electronegativity values, from low to high?

Biochemistry and the Organization of Cells

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids: How Structure Conveys Information

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of RNA

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

Filters

If the pH of 1 liter of a 1.0 M carbonate buffer is 7.0, what is the molar ratio of H₂CO₃ to HCO₃−? (pK = 6.37)

What is the pH of a solution with [H⁺] = 10 mM?

Which has the greater K_a, a weak acid or a strong acid?