2
Chemical Foundations
test bankChemical Foundations
Section 2.1
1. Covalent bonds between which of the following pairs of atoms are nonpolar?
a. C–C
b. C–H
c. O–H
d. a and b
Ans: d
Question Type: Multiple Choice
Chapter: 2.1
Blooms: Remembering
Difficulty: Easy
2. Which of the following is a noncovalent interaction?
a. hydrophobic effect
b. ionic interactions
c. van der Waals interactions
d. all of the above
Ans: d
Question Type: Multiple Choice
Chapter: 2
Blooms: Remembering
Difficulty: Easy
3. Which of the following is the strongest interaction?
a. hydrogen bond
b. ionic bond
c. phosphoanhydride bond
d. van der Waals interaction
Ans: c
Question Type: Multiple Choice
Chapter: 2
Blooms: Understanding
Difficulty: Easy
4. Which of the following is the weakest interaction?
a. hydrogen bond
b. ionic bond
c. phosphoanhydride bond
d. van der Waals interaction
Ans: d
Question Type: Multiple Choice
Chapter: 2
Blooms: Understanding
Difficulty: Easy
5. When two atoms differing in electronegativity are joined in a covalent bond, then the:
a. electrons are shared equally between the atoms.
b. bond is nonpolar.
c. resulting compound is devoid of any dipole moment.
d. atom with the greater electronegativity attracts the bonded electrons more strongly.
Ans: d
Question Type: Multiple Choice
Chapter: 2
Blooms: Understanding
Difficulty: Moderate
6. The interactions between two proteins such as an antibody and an antigen or a hormone and its receptor are quite strong despite the fact that these interactions consist of relatively weak noncovalent bonds. How can this be?
Ans: Two proteins can bind tightly because of molecular complementarity, in which multiple noncovalent bonds participate. Although each individual bond is weak, the cumulative effect of many noncovalent bonds is a relatively strong and highly specific interaction.
Question Type: Essay
Chapter: 2
Blooms: Analyzing
Difficulty: Moderate
7. What produces the dipole of a water molecule?
Ans: The dipole of a water molecule is caused by the difference in electronegativity between O and H. The oxygen atom has a greater electronegativity than the hydrogen atom. As a result, oxygen attracts the electrons in the O–H bond more strongly, and the oxygen side of the bond has a slight net negative charge. This results in a dipole moment.
Question Type: Essay
Chapter: 2.1
Blooms: Understanding
Difficulty: Moderate
Section 2.2
8. Which of the following is a negatively charged amino acid?
a. alanine
b. aspartate
c. glutamine
d. histidine
Ans: b
Question Type: Multiple Choice
Chapter: 2
Blooms: Remembering
Difficulty: Easy
9. Which of the following is/are a hydrophilic amino acid?
a. aspartate
b. serine
c. tryptophan
d. aspartate and serine
Ans: d
Question Type: Multiple Choice
Chapter: 2
Blooms: Remembering
Difficulty: Easy
10. Adenosine is a:
a. component of RNA.
b. nucleoside.
c. pyrimidine.
d. a and b
Ans: d
Question Type: Multiple Choice
Chapter: 2
Blooms: Remembering
Difficulty: Moderate
11. Which of the following is a monosaccharide?
a. fructose
b. galactose
c. glucose
d. all of the above
Ans: d
Question Type: Multiple Choice
Chapter: 2
Blooms: Remembering
Difficulty: Easy
12. Based on what you know about hydrophobic interactions, which of the following is/are composed of a bilayer?
a. a cell’s membrane
b. spontaneously aggregated phospholipids surrounding an aqueous interior
c. lipid vesicles that have budded off the cell’s membrane
d. all of the above
Ans: d
Question Type: Multiple Choice
Chapter: 2
Blooms: Remembering
Difficulty: Easy
13. You discover that you suffer from a deficiency in the amino acid tryptophan. At the pharmacy, you find both d-tryptophan and l-tryptophan supplements. Which do you purchase? Why?
Ans: You should choose l-tryptophan. All amino acids can exist as one of two stereoisomers (d or l) because of asymmetry around the α carbon. Proteins consist of the l form of amino acids, and as these stereoisomers possess distinct biological properties and are not readily interconverted, you should choose the form that is normally utilized by cells.