BIO 141: CHAPTER 2: ATOMS, IONS, AND MOLECULES:
TEST QUESTIONS WITH ACCURATE SOLUTIONS
What is cohesion? -- Answer ✔✔ The attraction between water molecules
What is adhesion? -- Answer ✔✔ The attraction between water molecules and a
substance other than water
Polar molecules such as glucose and alcohol dissolve in water as a result of the
___________ ___________ that form between those molecules and water -- Answer
✔✔ hydrogen bonds
Salts are ___________ compounds that both dissolve and dissociate when placed into
water -- Answer ✔✔ ionic
Acids and bases also ___________ in water -- Answer ✔✔ dissociate
___________ substances, such as triglycerides (fats) and cholesterol, require carrier
proteins to be transported within the blood because of their inability to dissolve within
water -- Answer ✔✔ Hydrophobic
,___________ molecules have both polar and nonpolar regions. They do not
completely dissolve, nor are they completely excluded when placed into water --
Answer ✔✔ Amphipathic
What distinguishes the tertiary and quaternary level of organization of a protein? --
Answer ✔✔ Quaternary structure is the structure present between multiple
polypeptide chains
Tertiary structure is the final three-dimensional shape of a completed polypeptide chain
Compare and contrast what occurs when a substance dissolves in water with a
substance that dissolves and dissociates in water. Include examples of specific
substances. -- Answer ✔✔ Comparison:
1. They both involve a substance mixing into water and becoming evenly
distributed
2. In both processes, water’s polar nature plays a role in surrounding the dissolved
particles
Contrast :
1. In dissociation, the substance dissolves and breaks into ions while in
dissolution(no dissociation), the substance dissolves but stays intact as molecules
2. Dissociation include substances that are ionic compounds e.g. salt (NaCl) while
dissolution(no dissociation) includes substances that are covalent compounds e.g.
Sugar (C₁₂H₂₂O₁₁)
3. In terms of electrical conductivity, substances that dissolved and dissociate do
conduct electricity whereas substances that dissolves do not conduct electricity.
Temperature stabilization is dependent on which two properties of water? -- Answer
✔✔ high specific heat capacity
High heat of vaporization
True/False: a carbon atom has six electrons in its outermost shell? -- Answer ✔✔ false
, True/False: the bond between a carbon and hydrogen atom is a polar bond -- Answer
✔✔ false
True/False: oxygen and nitrogen have a stronger electronegativity than carbon --
Answer ✔✔ true
True/False: Bonds between carbon and other atoms are relatively unstable and readily
dissociate, resulting in the formation of new molecules -- Answer ✔✔ false
True/False: a carbon skeleton comes in a variety of shapes: straight, ring-like, or
branched -- Answer ✔✔ true
True/False: carbon atoms are able to form four bonds -- Answer ✔✔ true
True/False: The bonds between water molecules are stable -- Answer ✔✔ false
True/False: as temperature drops the bonds between water molecules are less likely to
break -- Answer ✔✔ true
True/False: ice is denser than liquid water at all temperatures -- Answer ✔✔ false
True/False: the polar covalent bonds between hydrogen and oxygen atoms within a
water molecule create slight positively and negatively charged ends of the molecule --
Answer ✔✔ true
True/False: the fluid nature of water is due to hydrogen bonds continually breaking and
re-forming -- Answer ✔✔ true
True/False: a hydrogen atom of one water molecular binds via a hydrogen bond to a
hydrogen atom of another water molecule -- Answer ✔✔ false
TEST QUESTIONS WITH ACCURATE SOLUTIONS
What is cohesion? -- Answer ✔✔ The attraction between water molecules
What is adhesion? -- Answer ✔✔ The attraction between water molecules and a
substance other than water
Polar molecules such as glucose and alcohol dissolve in water as a result of the
___________ ___________ that form between those molecules and water -- Answer
✔✔ hydrogen bonds
Salts are ___________ compounds that both dissolve and dissociate when placed into
water -- Answer ✔✔ ionic
Acids and bases also ___________ in water -- Answer ✔✔ dissociate
___________ substances, such as triglycerides (fats) and cholesterol, require carrier
proteins to be transported within the blood because of their inability to dissolve within
water -- Answer ✔✔ Hydrophobic
,___________ molecules have both polar and nonpolar regions. They do not
completely dissolve, nor are they completely excluded when placed into water --
Answer ✔✔ Amphipathic
What distinguishes the tertiary and quaternary level of organization of a protein? --
Answer ✔✔ Quaternary structure is the structure present between multiple
polypeptide chains
Tertiary structure is the final three-dimensional shape of a completed polypeptide chain
Compare and contrast what occurs when a substance dissolves in water with a
substance that dissolves and dissociates in water. Include examples of specific
substances. -- Answer ✔✔ Comparison:
1. They both involve a substance mixing into water and becoming evenly
distributed
2. In both processes, water’s polar nature plays a role in surrounding the dissolved
particles
Contrast :
1. In dissociation, the substance dissolves and breaks into ions while in
dissolution(no dissociation), the substance dissolves but stays intact as molecules
2. Dissociation include substances that are ionic compounds e.g. salt (NaCl) while
dissolution(no dissociation) includes substances that are covalent compounds e.g.
Sugar (C₁₂H₂₂O₁₁)
3. In terms of electrical conductivity, substances that dissolved and dissociate do
conduct electricity whereas substances that dissolves do not conduct electricity.
Temperature stabilization is dependent on which two properties of water? -- Answer
✔✔ high specific heat capacity
High heat of vaporization
True/False: a carbon atom has six electrons in its outermost shell? -- Answer ✔✔ false
, True/False: the bond between a carbon and hydrogen atom is a polar bond -- Answer
✔✔ false
True/False: oxygen and nitrogen have a stronger electronegativity than carbon --
Answer ✔✔ true
True/False: Bonds between carbon and other atoms are relatively unstable and readily
dissociate, resulting in the formation of new molecules -- Answer ✔✔ false
True/False: a carbon skeleton comes in a variety of shapes: straight, ring-like, or
branched -- Answer ✔✔ true
True/False: carbon atoms are able to form four bonds -- Answer ✔✔ true
True/False: The bonds between water molecules are stable -- Answer ✔✔ false
True/False: as temperature drops the bonds between water molecules are less likely to
break -- Answer ✔✔ true
True/False: ice is denser than liquid water at all temperatures -- Answer ✔✔ false
True/False: the polar covalent bonds between hydrogen and oxygen atoms within a
water molecule create slight positively and negatively charged ends of the molecule --
Answer ✔✔ true
True/False: the fluid nature of water is due to hydrogen bonds continually breaking and
re-forming -- Answer ✔✔ true
True/False: a hydrogen atom of one water molecular binds via a hydrogen bond to a
hydrogen atom of another water molecule -- Answer ✔✔ false
