Question 1

Micelles are stabilized in water by interactions of nonpolar molecules with each other.

Accepted Answer

A) True 
 B)False  True

Question 2

Oil and water do not form a solution due to ________.

Accepted Answer

A) the hydrophobic effect 
B) the inability of oil to hydrogen bond with water 
C) the nonpolarity of oil 
D) All of the above. 
E) A and C only. 
A) the hydrophobic effect 
B) the inability of oil to hydrogen bond with water 
C) the nonpolarity of oil 
D) All of the above. 
E) A and C only. D

Question 3

The imidazolium ion has a pKa = 7.0.Imidazolium buffers can be prepared for pH values of

Accepted Answer

A) 6.5 to 7.5. 
B) 6.1 to 7.1. 
C) 5.5 to 8.5. 
D) 6.0 to 8.0. 
E) 6.0 to 7.5. 
A) 6.5 to 7.5. 
B) 6.1 to 7.1. 
C) 5.5 to 8.5. 
D) 6.0 to 8.0. 
E) 6.0 to 7.5. D

Question 4

Compounds that ionize when dissolved in water are called ________.

Accepted Answer

A) electrolytes 
B) polar compounds 
C) hydrophobic compounds 
D) amphipathic compounds 
A) electrolytes 
B) polar compounds 
C) hydrophobic compounds 
D) amphipathic compounds

Question 5

If human blood is not maintained at close to pH = 7.4,a person can develop

Accepted Answer

A) acidosis. 
B) alkalosis. 
C) diabetes. 
D) Both A and B. 
E) None of the above. 
A) acidosis. 
B) alkalosis. 
C) diabetes. 
D) Both A and B. 
E) None of the above.

Question 6

Solutes diffuse more slowly in cytoplasm than in water because of

Accepted Answer

A) the higher viscosity of water. 
B) the higher heat of vaporization of water. 
C) the presence of many crowded molecules in the cytoplasm. 
D) the absence of charged molecules inside cells. 
A) the higher viscosity of water. 
B) the higher heat of vaporization of water. 
C) the presence of many crowded molecules in the cytoplasm. 
D) the absence of charged molecules inside cells.

Question 7

Which molecule or ion below is amphipathic?

Accepted Answer

A) H₂NCH₂COOH (glycine) 
B) H₂O 
C) CH₃(CH₂)14COO- 
D) CH₃CH₂CH₂CH₂CH₃ 
A) H₂NCH₂COOH (glycine) 
B) H₂O 
C) CH₃(CH₂)14COO- 
D) CH₃CH₂CH₂CH₂CH₃

Question 8

The equilibrium constant of water (Keq)is the rate that dissociation of the molecule occurs at room temperature.

Accepted Answer

A) True 
 B)False

Question 9

Synthetic compounds used as buffers are not as valuable for experiments as naturally occurring compounds used as buffers.

Accepted Answer

A) True 
 B)False

Question 10

Hyperventilation can result in alkalosis because there is excessive loss of carbon dioxide and,therefore a loss of carbonic acid.

Accepted Answer

A) True 
 B)False

Question 11

Hydrogen bonds can occur when hydrogen is covalently bonded to atoms like nitrogen and oxygen.What property of nitrogen and oxygen is important for this?

Accepted Answer

A) Atomic mass. 
B) Ionizability. 
C) Hydrophobicity. 
D) Electronegativity. 
A) Atomic mass. 
B) Ionizability. 
C) Hydrophobicity. 
D) Electronegativity.

Question 12

Poorly soluble molecules such as lipids and nucleoside bases can be made more soluble in cells by attaching ________ to them.

Accepted Answer

A) water 
B) oxygen 
C) carbohydrates 
D) salt ions 
A) water 
B) oxygen 
C) carbohydrates 
D) salt ions

Question 13

Compare solution A with pH = 4 to solution B with pH = 6.

Accepted Answer

A) The concentration of hydronium ion in solution A is twice that in solution B. 
B) Solution A has greater buffering capacity than solution B. 
C) The concentration of hydronium ion in solution A is 100 times that in solution B. 
D) The hydroxide concentrations are equal in the two solutions since pH only measures the concentration of H+. 
A) The concentration of hydronium ion in solution A is twice that in solution B. 
B) Solution A has greater buffering capacity than solution B. 
C) The concentration of hydronium ion in solution A is 100 times that in solution B. 
D) The hydroxide concentrations are equal in the two solutions since pH only measures the concentration of H+.

Question 14

The ionic composition of sea water and blood plasma is similar,and this is evidence that the earliest form of life lived in oceans.

Accepted Answer

A) True 
 B)False

Question 15

Which statement below is true about the relative lifetime of a hydrogen bond,compared to the rate of water's ionization to hydroxide ions and hydronium ions?

Accepted Answer

A) The strength of hydrogen bonding makes its dissociation much slower than the ionization of water. 
B) The rate of dissociation of a hydrogen bond is the same order of magnitude as the rate of ionization of water. 
C) The two rates are linked in such a way that the more the water is ionized,the stronger and longer lasting hydrogen bonding will be. 
D) The lifetime of a water molecule before it is ionized is about 109 greater than the lifetime of a hydrogen bond. 
A) The strength of hydrogen bonding makes its dissociation much slower than the ionization of water. 
B) The rate of dissociation of a hydrogen bond is the same order of magnitude as the rate of ionization of water. 
C) The two rates are linked in such a way that the more the water is ionized,the stronger and longer lasting hydrogen bonding will be. 
D) The lifetime of a water molecule before it is ionized is about 109 greater than the lifetime of a hydrogen bond.

Question 16

Attractions of oppositely charged functional groups of proteins are sometimes called ________.

Accepted Answer

A) salt bridges or ion pairing 
B) disulfide bridges 
C) London bridges 
D) hydrophilic bridges 
A) salt bridges or ion pairing 
B) disulfide bridges 
C) London bridges 
D) hydrophilic bridges

Question 17

Water molecules clustered about nonpolar molecules contribute to hydrophobic interactions because

Accepted Answer

A) their number is minimized to increase the total entropy of water. 
B) nonpolar molecules are more highly organized than polar molecules. 
C) water molecules in the cell are more organized in the regions away from the nonpolar molecule. 
D) All of the above. 
E) B and C. 
A) their number is minimized to increase the total entropy of water. 
B) nonpolar molecules are more highly organized than polar molecules. 
C) water molecules in the cell are more organized in the regions away from the nonpolar molecule. 
D) All of the above. 
E) B and C.

Question 18

Some ions such as thiocyanate that are poorly solvated in water and can enhance the solubility of nonpolar compounds in water by disordering the water molecules are called ________.

Accepted Answer

A) azeotropes 
B) hydrophobic ions 
C) zeolytes 
D) chaotropes 
A) azeotropes 
B) hydrophobic ions 
C) zeolytes 
D) chaotropes

Question 19

How does the ion-product of water,Kw,relate to the equilibrium constant,Keq,for the dissociation reaction of water?

Accepted Answer

A) Kw is found by multiplying Keq by the concentration of water. 
B) Kw just another symbol for Keq ,so they are equal. 
C) Kw is found by dividing Keq by the ideal gas constant. 
D) Kw is found by multiplying Keq by the concentrations of hydronium ion and hydroxide ion. 
A) Kw is found by multiplying Keq by the concentration of water. 
B) Kw just another symbol for Keq ,so they are equal. 
C) Kw is found by dividing Keq by the ideal gas constant. 
D) Kw is found by multiplying Keq by the concentrations of hydronium ion and hydroxide ion.

Question 20

The pH of a 10-⁴ M solution of HCl is

Accepted Answer

A) 3. 
B) 3.5. 
C) 4. 
D) 4.5. 
E) greater than 4.5. 
A) 3. 
B) 3.5. 
C) 4. 
D) 4.5. 
E) greater than 4.5.

Exam 2: Water

Micelles are stabilized in water by interactions of nonpolar molecules with each other.

Oil and water do not form a solution due to ________.

The imidazolium ion has a pKa = 7.0.Imidazolium buffers can be prepared for pH values of

Compounds that ionize when dissolved in water are called ________.

If human blood is not maintained at close to pH = 7.4,a person can develop

Solutes diffuse more slowly in cytoplasm than in water because of

Which molecule or ion below is amphipathic?

The equilibrium constant of water (Keq)is the rate that dissociation of the molecule occurs at room temperature.

Synthetic compounds used as buffers are not as valuable for experiments as naturally occurring compounds used as buffers.

Hyperventilation can result in alkalosis because there is excessive loss of carbon dioxide and,therefore a loss of carbonic acid.

Hydrogen bonds can occur when hydrogen is covalently bonded to atoms like nitrogen and oxygen.What property of nitrogen and oxygen is important for this?

Poorly soluble molecules such as lipids and nucleoside bases can be made more soluble in cells by attaching ________ to them.

Compare solution A with pH = 4 to solution B with pH = 6.

The ionic composition of sea water and blood plasma is similar,and this is evidence that the earliest form of life lived in oceans.

Which statement below is true about the relative lifetime of a hydrogen bond,compared to the rate of water's ionization to hydroxide ions and hydronium ions?

Attractions of oppositely charged functional groups of proteins are sometimes called ________.

Water molecules clustered about nonpolar molecules contribute to hydrophobic interactions because

Some ions such as thiocyanate that are poorly solvated in water and can enhance the solubility of nonpolar compounds in water by disordering the water molecules are called ________.

How does the ion-product of water,Kw,relate to the equilibrium constant,Keq,for the dissociation reaction of water?

The pH of a 10-⁴ M solution of HCl is

Introduction to Biochemistry

Amino Acids and the Primary Structures of Proteins

Proteins: Three-Dimensional Structure and Function

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

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