Chapter 2
A) It has 6 protons in its nucleus.
B) It has 12 neutrons in its nucleus.
C) It has 6 electrons orbiting the nucleus.
D) Its atomic number is 6.
E) Its atomic weight is 12.
Answer: B
Using the information in Table 2.1, calculate the molecular weight of ethanol, C2H5OH.
A) 96
B) 46
C) 34
D) 33
E) The answer cannot be determined.
Answer: B
3) Antacids neutralize acid by the following reaction. Identify the salt in the following equation:
Mg(OH)2 + 2HCl → MgCl2 + H2O
A) Mg(OH)2
B) HCl
C) MgCl2
D) H2O
E) None of the answers is correct.
Answer: C
4) Which of the following statements is FALSE?
A) Salts readily dissolve in water.
B) Water molecules are formed by hydrolysis.
C) Water freezes from the top down.
D) Water is formed as a part of a dehydration synthesis reaction.
E) Water is a polar molecule.
Answer: B
5) Which of the following is the type of bond holding K+ and I- ions in KI?
A) ionic bond
B) covalent bond
C) hydrogen bond
Answer: A
6) Which of the following is the type of bond between molecules of water in a beaker of water?
A) ionic bond
B) covalent bond
C) hydrogen bond
Answer: C
7) What is the type of bond holding hydrogen and oxygen atoms together in a single H2O molecule?
A) ionic bond
B) covalent bond
C) hydrogen bond
Answer: B
8) Identify the following reaction: Glucose + Fructose → Sucrose + Water
A) dehydration synthesis reaction
B) hydrolysis reaction
C) exchange reaction
D) reversible reaction
E) ionic reaction
Answer: A
9) Identify the following reaction: Lactose + H2O → Glucose + Galactose
A) dehydration synthesis reaction
B) hydrolysis reaction
C) exchange reaction
D) reversible reaction
E) ionic reaction
Answer: B
10) Identify the following reaction: HCl + NaHCO3 → NaCl + H2CO3
A) dehydration synthesis reaction
B) hydrolysis reaction
C) exchange reaction
D) reversible reaction
E) ionic reaction
Answer: C
11) Identify the following reaction: NH4OH ⇌ NH3 + H2O
A) dehydration synthesis reaction
B) hydrolysis reaction
C) exchange reaction
D) reversible reaction
E) ionic reaction
Answer: D
12) Which type of molecule contains the alcohol glycerol?
A) carbohydrate
B) phospholipids
C) DNA
D) protein
Answer: B
13) Which type of molecule is composed of (CH2O) units?
A) carbohydrate
B) lipid
C) nucleic acid
D) protein
Answer: A
14) Which type of molecule contains -NH2 (amino) groups?
A) carbohydrate
B) triglycerides
C) nucleic acid
D) protein
Answer: D
15) Which type of molecule NEVER contains a phosphate group?
A) triglycerides
B) phospholipid
C) nucleic acid
D) ATP
Answer: A
16) Based upon the valence numbers of the elements magnesium (2) and hydrogen (1), predict how many covalent bonds would form between these atoms to achieve the full complement of electrons in their outermost energy shells.
A) one
B) two
C) three
D) four
Answer: B
Using the information in Table 2.1, calculate the number of moles in 92 grams of ethanol,
C2H5OH.
A) 1
B) 2
C) 3
D) 4
E) The answer cannot be determined.
Answer: B
18) Which of the following statements regarding protein structure is FALSE?
A) The primary structure is formed by covalent bonding between amino acid subunits.
B) Secondary structures are formed only from hydrogen bonds.
C) Tertiary structures are formed only from covalent bonds.
D) Quaternary structures involved multiple polypeptides.
Answer: C
19) Which of the following pairs is mismatched?
A) NaOH ⇌ Na++ OH-— base
B) HF ⇌ H++ F-— acid
C) MgSO4⇌ Mg2++ SO42- — salt
D) KH2PO4⇌ K++ H2PO4- — acid
E) H2SO4⇌ 2H++ SO42- — acid
Answer: D
20) Table 2.2
NaOH ⇌ Na+ + OH- — base
HF ⇌ H+ + F- - acid
MgSO4 ⇌ Mg2+ + SO42- — salt
KH2PO4 ⇌ K+ + H2PO4- — acid
H2SO4 ⇌ 2H+ + SO42- — salt
Which of the following statements about the reactions in Table 2.2 is FALSE?
A) They are exchange reactions.
B) They are ionization reactions.
C) They occur when the reactants are dissolved in water.
D) They are dissociation reactions.
E) They are reversible reactions.
Answer: A
21) What is the type of weak bond between the hydrogen of one molecule and the nitrogen of another molecule, where the two don't actively share an electron?
A) ionic bond
B) covalent bond
C) hydrogen bond
D) disulfide bond
E) hydrophobic bond
Answer: C
22) What is the type of strong chemical bond between carbon, hydrogen, and oxygen atoms in a single organic molecule?
A) ionic bond
B) covalent bond
C) hydrogen bond
Answer: B
23) What is the type of bond between ions in salt?
A) ionic bond
B) covalent bond
C) hydrogen bond
Answer: A
24) A scientist wants to perform a test that will indicate whether a nucleic acid sample is composed of RNA or DNA. Testing for the presence of which of the following is most appropriate in this situation?
A) phosphate
B) nitrogen
C) guanine
D) uracil
E) thymine
Answer: D
25) Structurally, ATP is most like which type of molecule?
A) carbohydrate
B) lipid
C) protein
D) nucleic acid
Answer: D
26) What do genes consist of?
A) carbohydrates
B) lipids
C) proteins
D) nucleic acids
Answer: D
27) Which molecule is composed of a chain of amino acids?
A) carbohydrate
B) lipid
C) protein
D) nucleic acid
Answer: C
28) Which are the primary molecules making up plasma membranes in cells?
A) carbohydrates
B) lipids
C) proteins
D) nucleic acids
Answer: B
29) The antimicrobial drug imidazole inhibits sterol synthesis. This would most likely interfere with
A) bacterial cell walls.
B) fungal cell walls.
C) eukaryotic plasma membranes.
D) prokaryotic plasma membranes.
E) genes.
Answer: C
30) In Figure 2.1, which is an alcohol?
A) a
B) b
C) c
D) d
E) e
Answer: C
31) Which compound in Figure 2.1 is an ester?
- A) a
- B) b
- C) c
- D) d
- E) e
Answer: D
32) Which compound in Figure 2.1 is an organic acid?
- A) a
- B) b
- C) c
- D) d
- E) e
Answer: A
33) Most amino acids found in cells demonstrate what type of chirality?
A) L-isomers
B) D-isomers
C) C-isomers
D) B-isomers
E) A-isomers
Answer: A
What kind of bond is at the arrow in Figure 2.3?
A) disulfide bridge
B) double covalent bond
C) hydrogen bond
D) ionic bond
E) peptide bond
Answer: E
35) An E. coli culture that has been growing at 37°C is moved to 25°C. Which of the following changes must be made in its plasma membrane to help it cope with the decrease in temperature?
A) The number of phosphate groups must increase.
B) The viscosity must increase.
C) The number of saturated chains must increase.
D) The number of unsaturated chains must increase.
E) No changes are necessary
Answer: D
36) Radioisotopes are frequently used to label molecules in a cell. The fate of atoms and molecules in a cell can then be followed. Assume Saccharomyces cerevisiae is grown in a nutrient medium containing the radioisotope 35S. After a 48-hour incubation, the 35S would most likely be found in the S. cerevisiae's
A) carbohydrates.
B) nucleic acids.
C) water.
D) lipids.
E) proteins.
Answer: E
37) Radioisotopes are frequently used to label molecules in a cell. The fate of atoms and molecules in a cell can then be followed. Assume Saccharomyces cerevisiae is grown in a nutrient medium containing the radioisotope 32P. After a 48-hour incubation, the majority of the 32P would be found in the S. cerevisiae's
A) plasma membrane.
B) cell wall.
C) water.
D) proteins.
E) carbohydrates.
Answer: A
38) Starch, dextran, glycogen, and cellulose are polymers of
A) amino acids.
B) glucose.
C) fatty acids.
D) nucleic acids.
E) acids.
Answer: B
39) Which of the following is a base?
A) C2H5OCOOH → H++ C2H5OCOO-
B) C2H5OH
C) NaOH → Na++ OH-
D) H2O → H++ OH-
E) H2CO
Answer: C
40) Two glucose molecules are combined to make a maltose molecule. What is the chemical formula for maltose?
A) C3H6O3
B) C6H12O6
C) C12H24O12
D) C12H22O11
E) C12H23O10
Answer: D
41) If an amino acid contained a hydrocarbon (a group of multiple carbons and hydrogens linked together) as its side group, in which of the following categories could it be appropriately designated?
A) hydrophilic
B) polar
C) nonpolar
D) basic
E) acidic
Answer: C