1. The amount of mass per unit volume refers to the
A: density
B: specific mass
C: specific volume
D: pressure
E: weight per volume %
2. A substance which cannot be further decomposed by ordinary chemical reaction is
A: water B: air C: glucose D: lead E: DNA
3. If ΔH of a reaction is negative quantity, the reaction is definitely
A: endergonic B: exergonic C: irreversible D: endothermic E: exothermic
4. Choose the element whose atoms show the greatest affinity for an additional electron
A: N B: O C: F D: Cl E: Na
5. The high boiling point of water in comparison with a similar compound is due to the
A: van der Waals force
B: hydrogen bond
C: dipole－dipole force
D: polar covalent bond
E: small size of water molecule
6. The normality of phosphoric acid solution that has a concentration of 3 M is
A: 2N B: 3N C: 6N D: 9N E: 12N
7. The addition of a catalyst to a reaction changes the
1. enthalpy 2. entropy 3. activation energy 4. reaction rate
A: 2 B: 1,2 C: 1,3 D: 2,3 E: 3,4
8. The pH of a solution that has a proton concentration of 1×10-4 mol/L is
A: log(1×10-4) B: 10 C: -4 D: 4 E: 10-14/ 1×10-4
9. According to the Bronsted theory an acid is
A: a proton acceptor
B: a proton donor
C: an electron acceptor
D: an electron donor
E: a hydroxide ion acceptor
10. During the electrolysis of copper chloride, the substance liberated at the anode is
A: copper B: hydrogen C: chlorine D: chloride ions E: copper ions
11. The precipitate formed when carbon dioxide is bubbled into calcium hydroxide solution is
A: CaCl2 B: CaCO3 C: H2CO3 D: Ca(OH)2 E: CO2
12. The principal energy shell 4 has
A: 4 orbitals B: 4 subshells C: 4 main levels D: 4 electrons E: 8 electrons
13. The element with the atomic number of 20 is a
A: nonmetal B: transition element C: metal D: semimetal E: noble gas
14. The element with the atomic number of 41 is a
A: nonmetal B: transition element C: metal D: semimetal E: halogen
15. 35Cl and 37Cl are two isotopes of chlorine. Which of the following properties do they have in common?
1: number of neutrons
2: number of protons
3: atomic mass
4: chemical reactivity
A: 1,3 B: 2,4 C: 1,4 D: 2,3,4 E: 1,2,3
16. An atom has 6 protons and 8 neutrons, its
1: atomic number is 6
2: mass number is 14
3: number of electrons is 6
4: electrical charge is +6
A: 1,2,3 B: 1,2,4 C: 1,4 D: 2,3 E: 4
17. Protons
1: occur in the nucleus
2: account for almost the entire mass of the atom, except in hydrogen
3: their number in an atom is equal to the number of neutrons
4: their number in an atom is equal to the number of electrons
A: 1 B: 1,2 C: 1,2,3 D: 1,4 E: 2,4
18. Electrons
1: have mass of 5.48×10-4 g
2: have negligible mass
3: their number in an atom is equal to the number of protons
4: their number in an atom is equal to the number of neutrons
A: 1 B: 1,4 C: 1,3 D: 2,4 E: 2,3
19. Consider methane ( CH4 ) molecule
1: The molecule is somewhat polar since the carbon and hydrogen atoms have different electronegativities
2: The bonding electrons are equally shared by carbon and hydrogen in the C－H bonds
3: The shape of the molecule is tetrahedral
4: The electron sharing in the covalent bond ensures the electronic configuration of neon for both atoms
A: 1,3,4 B: 2,3,4 C: 3 D: 2,4 E: 2,3
20. Which statements are true for the ammonium ion ?
1: The ion is held together by covalent bonds
2: One of the four hydrogen atoms forms an ionic bond with the nitrogen
3: The positive charge is localized on one of the hydrogen atoms
4: One of the four hydrogen atoms has accepted two electrons, donated by the nitrogen atom
A: 1,3,4 B: 2,3,4 C: 2,3 D: 1,4 E: 1,3
21. Compare the two molecules
1: both contain polar covalent bonds
2: both can form hydrogen bond in pure state
3: both are liquids at 298 K
4: the intermolecular forces between the identical molecules of the two compounds have approximately
the same strength
A: 1 B: 1,2 C: 1,2,3 D: 1,3,4 E: 2,3,4
22. Consider two acids
HA1 for which pKa1 = 7.2
HA2 for which pKa2 = 8.1
1: both are weak acids
2: HA1 is a stronger proton donor than HA2
3: HA2 had a stronger conjugate base pair than the conjugate base of HA1
4: HA1 is a weaker acid than HA2
A: 1 B: 1,2 C: 1,2,3 D: 2,3,4 E: 1,3,4
23. Which of the following species is the weakest proton acceptor ?
A: NH3 (Kb = 1.8×10-5) B: H2O C: OH－ D: PO43－ E: HPO42－
24. CH4 (g) ＋ 2H2S (g) ⇔CS2 (g) ＋ 4H2 (g)
The reaction is reversible and endothermic to the right. Which of the following changes (when applied to
the system in equilibrium state) will shift the reaction to the right?
1: increase the temperature
2: decrease the pressure
3: remove H2
4: remove CH4
A: 1,2 B: 1,2,3 C: 1,3 D: 1,3,4 E: 3,4
25. N2 (g) ＋ O2⇔2NO (g)
The reaction is reversible and endothermic to the right. Which of the following changes (when applied to
the system in equilibrium state) will shift the reaction to the left?
1: increase the pressure
2: decrease the temperature
3: remove NO
4: remove O2
A: 1 B: 1,2 C: 1,3 D: 2,3 E: 2,4
26. The net ionic equation for the reaction of sodium bicarbonate with hydroiodic acid is
A: Na＋(aq) ＋ HCO3－(aq) ＋ H＋(aq) ＋ I－(aq) →Na＋(aq) ＋ I－(aq) ＋ H2O ＋ CO2 (g)
B: H＋(aq) ＋ HCO3－(aq) →H2O ＋ CO2 (g)
C: Na＋(aq) ＋ I－(aq) →NaI (s)
D: 2H＋(aq) ＋ CO32－(aq) →H2O ＋CO2 (g)
E: HCO3－(aq) ＋ HI (aq) →I－(aq) ＋ H2O ＋ CO2 (g)
27. The net ionic equation for the reaction of calcium carbonate with hydrochloric acid is
A: Ca2＋(aq) ＋ CO32－(aq) ＋ 2H＋(aq) ＋ 2Cl－(aq) →Ca2＋(aq) ＋ 2Cl－(aq) ＋ H2O ＋ CO2 (g)
B: CO32－(aq) ＋ 2H＋(aq) →H2O ＋ CO2 (g)
C: Ca2＋(aq) ＋ 2Cl－(aq) →CaCl2 (s)
D: CO32－(aq) ＋ 2HCl (aq) →H2O ＋ CO2 (g) ＋ 2Cl－(aq)
E: CaCO3 (s) ＋ 2H＋(aq) →Ca2＋(aq) ＋ H2O ＋ CO2 (g)
28. The pH of a sulfuric acid solution is 4
1: The hydronium ion concentration in the solution is 10－4 mol/L
2: The concentration of the H2SO4 solution is 5×10－5 mol/L
3: The hydroxide ion concentration is 10－7 mol/L
4: The ion product of water has changed to 10－10 compared to pure water
A: 1 B: 1,2 C: 2,3 D: 3,4 E: 1,4
29. Which of the following solutions has the highest hydroxide ion concentration?
A: 0.1 M HCl
B: 0.1 M H2SO4
C: a buffer solution with pH=5
D: a buffer solution with pOH=12
E: pure water
30. Given the following half reactions with their standard reduction potentials, which reaction will be
spontaneous?
I2 (s) ＋ 2e－←→2I－(aq) ε0 = ＋0.54 V
Br2 (aq) ＋ 2e－←→2Br－(aq) ε0 = ＋1.07 V
A: Br2＋ I2→2Br－＋ 2I－
B: 2Br－ ＋ 2I－→Br2＋ I2
C: Br2＋ 2I－→2Br－＋I2
D: 2Br－ ＋ I2→Br2＋2I－
E: They will not react since both are electronegative halogens
31. Given the following half reactions with their standard reduction potentials, which reaction will not be
spontaneous?
Br2 (aq) ＋ 2e－←→2Br－(aq) ε0 = ＋1.07 V
Cl2 (aq) ＋ 2e－←→2Cl－(aq) ε0 = ＋1.36 V
1. 2Br－＋ Cl2→Br2＋ 2Cl－
2. Br2＋ 2Cl－ →2Br－ ＋ Cl2
3. 2Br－ ＋ 2Cl－→Br2＋ Cl2
4. Br2＋ Cl2→2Br－ ＋ 2Cl－
A: 1 B: 1,3 C: 2,4 D: 2,3,4 E: 1,2,3,4
32. Which of the following atoms has the largest atomic radius?
A: Li B: Na C: K D: Rb E: Cs
33. The pH of a 0.01 M KOH solution is
A: 12 B: 10－2 C: 2 D: －log 0.01 E: 14－log 0.01
34. In a standard electrochemical cell the two half cells are
Cu (s)／CuSO4 (aq) ε0 = ＋0.34V
Zn (s)／ZnSO4 (aq) ε0 = －0.76 V
1: Cu metal is the anode
2: Zn metal looses electrons
3: During operation the Zn electrode becomes smaller
4: The redox reaction is : Cu (s) ＋ ZnSO4 (aq) →Zn (s) ＋ CuSO4 (aq)
A: 1 B: 2,3 C: 3,4 D: 2,3,4 E: 1,2,3,4
35. Carbon atoms of diamond are held together by
A: intermolecular forces
B: ionic bonds
C: covalent bonds
D: van der Waals forces
E: nonbonding electrons
36. 2 moles of methane (CH4) gas under STP (standard temperature and pressure) occupies what volume ?
A: 2×6×1023 L
B: 2 L
C: 44.8 L
D: 273 L
E: indefinite volume
37. Which of the next statements are properties of the halogens ?
1: They lack one electron to the noble gas configuration
2: They are likely to undergo reduction
3: They form diatomic molecules
4: They exhibit high ionization energies
A: 1 B: 1,2 C: 2,4 D: 1,2,3 E: 1,2,3,4
38. Which of the next statements are the properties of metals ?
1: Metals exhibit high electron affinity
2: Metals are reducing agents
3: Metals tend to loose electron(s)
4: Metals tend to form molecules with covalent bonds
A: 1,2 B: 2,3 C: 2,4 D: 3,4 E: 1,2,3,4
39. An acidic solution is produced by which of the next salts ?
1: Cu(NO3)2 2: Na2CO3 3: (NH4)2SO4 4: K2SO4
A: 1,2 B: 2,3 C: 3,4 D: 1,3 E: 1,3,4
40. The oxidation number of nitrogen is the lowest in which molecule ?
A: NH3 B: HNO3 C: N2O5 D: HNO2 E: N2
41. Table salt is dissolved in water. One of the properties of the solution is
A: It boils at a lower temperature than water
B: It boils at a higher temperature than water
C: It freezes at a higher temperature than water
D: The solute particles in it do not dissociate
E: It is always isotonic with blood
42. Sugar is dissolved in water. Which of the following statements is/are untrue ?
1: The solution has a lower vapor pressure than water
2: The pressure measured above the solution is higher than the pressure measured above the solvent
3: The solution has a lower boiling point than water
4: The solution has a higher freezing point than water
A: 1,3 B: 1,4 C: 3,4 D: 1,3,4 E: 2,3,4
43. The speed of a chemical reaction may be influenced by
1: the concentration of the reactants
2: the temperature change
3: a catalyst
4: changing the physical state of the reactants
A: 1,2,3,4 B: 2,3,4 C: 2,3 D: 1,3 E: 3
44. Which of the following solution is/are isotonic with 0.1 M FeCl3 solution ?
1: 0.1 M Na2SO4 2: 0.1 M AlCl3 3: 0.2 M NaCl 4: 0.1 M Na3PO4
A: 1,2 B: 1,2,3 C: 2,3,4 D: 1,3,4 E: 2
45. The charges of the most common ions of K, Br, Mg, S are
A: －2, ＋2, －1, ＋1
B: ＋2, －2, ＋1, －1
C: ＋1, ＋2, －1, －2
D: ＋1, －1, ＋2, －2
E: ＋1, －2, －1, －2
46. Which of the compounds below contain no covalent bonds ?
1: KNO3 2: H2O 3: FeCl3 4: NH3
A: 1,3 B: 3 C: 1,2 D: 1,2,3 E: 3,4
47. A reaction that absorbs heat is
A: exergonic B: exothermic C: endergonic D: endothermic E: spontaneous
48. A buffer can be prepared from
1: 0.1 M NH3 and 0.1 M NH4Cl solutions
2: 0.1 M HBr and 0.1 M NaBr solutions
3: 0.1 M HNO3 and 0.1 M NaNO3 solutions
4: 0.1 M CH3COOH and 0.2 M CH3COONa solutions
A: 1,4 B: 2,3 C: 3,4 D: 2,3,4 E: 1,2,3,4
49. The pH of 0.005 M Ca(OH)2 solution is
A: 5×10－3 B: 2×10－12 C: 10－12 D: 2 E: 12
50. The pH of 0.005 M H2SO4 solution is
A: 5×10－3 B: 2×10－12 C: 10－12 D: 2 E: 12
51. The name of AgCl is ______
52. The name of K2SO4 is ______
53. The name of Al2(SO4)3 is ______
54.The name of NH4NO3 is ______
55. The name of Fe3(PO4)2 is ______
56. The formula of potassium chromate ______
57. The formula of sodium fluoride ______
58. The formula of magnesium sulfite ______
59. The formula of copper(Ⅱ) sulfate ______
60. The formula of iron(Ⅲ) bromide ______
61. Balance: ___ Cu ＋ ___ H2SO4→___ CuSO4＋ ___ SO2＋ ___ H2O
62. Balance: ___ KI ＋ ___ Cl2＋ ___ H2O →___ KIO3＋ ___ HCl
63. Balance: ___ Cr2O72－ ＋ ___ H2S＋ ___ H＋→___ Cr3＋ ＋ ___ S ＋ ___ H2O
64. Balance: ___ KMnO4＋ ___ FeCl2＋ ___ HCl →___ KCl ＋ ___ FeCl3＋ ___ MnCl2＋ ___ H2O
65. Balance: ___ Sn ＋ ___ NO3－ ＋ ___ H＋→___ SnO2＋ ___ NO ＋ ___ H2O
66. The angle between any two covalent bonds at a tetrahedral carbon is about
A: 104.5° B: 105° C: 109.5° D: 120° E: 180°
67. The carbon－oxygen double bond consists of
A: two σbonds
B: oneσand one πbond
C: twoπbonds
D: one σbond and one dative bond
E: oneπbond and one dative bond
68. The molecule, CH3－CH－CH3, could be oxidized to a three carbon
|
OH
A: aldehyde B: ketone C: carboxylic acid D: alkane E: alkene
69. The aldehyde group in acetaldehyde
A: can donate a hydrogen to H-bond
B: produces a ketone when oxidized
C: can form a ketal with an alcohol
D: is susceptible to oxidation
E: produces a carboxylic acid when reduced
70. Which compound is an acetal ?
71. What is the chief organic product (if any) in the following reaction ?
72. Which oxidation does not occur ?
73. The functional groups in are
A: an ester group
B: a carboxyl group
C: an ether and a keto group
D: an ether and an aldehyde group
E: an ester and an aldehyde group
74. The alcohol whose molecules can form the most hydrogen bonds between themselves is
A: methanol
B: ethanol
C: propanol
D: 1,2-ethanediol
E: 1,2,3-propanetriol
75. The product of the following reaction is
A: CH3－CH3
B: CH3－CH2－CH2－CH3
C: CH3－CH2－O－CH2－CH3
D: CH3－CH=CH－CH3
E: HO－CH2－CH2－CH2－CH2－OH
76. What is the chief organic product of the following reaction ?
77. What is the product (if any) of the following reaction ?
Ni, heat, pressure
CH2 = CH－CH2－CH3
A: H－CH = CH－CH3
B: CH3－CH2－CH2－CH3
C: Ni－CH2－CH2－CH2－CH3
D: Ni－CH = CH－CH2－CH3
E: no reaction occurs
78. When ethyl alcohol is heated in the presence of sulfuric acid, which organic product can form ?
A: ethylene glycol
B: polyethylene
C: ethylene
D: ethylene sulfate
E: ethenediol
79. Which carbons are correctly labeled ?
A: 1 and 2 are primary carbons
B: 2 and 3 are secondary carbons
C: 3 and 4 are tertiary carbons
D: 2 and 4 are quaternary carbons
E: 2 and 4 are tertiary carbons
80. Chloroform is
A: CH3Cl B: CH2Cl2 C: CHCl3 D: CCl4 E: None of them
81. Which list of functional groups, in the order shown, is correct for the following structural formulas ?
A: aldehyde, ketone:, carboxylic acid, ether, ester
B: carboxylic acid, ketone, aldehyde, ester, ether
C: carboxylic acid, ester, ketone, ether, aldehyde
D: carboxylic acid, ester, aldehyde, ether, ester
E: aldehyde, alcohol, carboxylic acid, ester, ether
82.
1: The reaction is neutralization
2: The reaction is condensation
3: The organic product is an ester
4: The reaction can be made more complete by using excess amount of acetic acid
A: 1,3,4 B: 2,3,4 C: 1,4 D: 3,4 E: 2,4
83.
1: group X is generally unreactive
2: group Y could be reduced to a ketone
3: group Z could undergo addition reaction
4: group Y could be involved in acid catalyzed dehydration
A: 1,2 B: 1,3 C: 1,3,4 D: 2,3,4 E: 1,2,3,4
84. Examine the following structures and select the correct statements
A: 1 and 2 are alkenes
B: 2,3 and 4 are structural isomers
C: 2,3 and 4 are optical isomers
D: 3 and 4 are alcohols
E: 4 is an alkyne
85. The carbon－carbon single bond in the CH3－CH3 molecule arises from the overlap of
A: a 2s orbital of one C with a 2s orbital of the other C
B: a 2p orbital of one C with a 2p orbital of the other C
C: a sp2 orbital of one C with a sp2 orbital of the other C
D: a sp3 orbital of one C with a sp3 orbital of the other C
E: a sp2 orbital of one C with a sp3 orbital of the other C
86. What is the correct order of increasing solubility in water for the following compounds?
(with the least soluble to be on the left end)
A: 1 ＜ 3 ＜ 2 B: 3 ＜ 1 ＜ 2 C: 2＜3＜1 D: 1＜2＜ 3 E: they are not soluble
87. Consider the OH groups in the following compounds
A: Numbers 1,2 and 5 are primary alcohol groups
B: Numbers 3,6 and 8 are secondary alcohol groups
C: Number 4 is a quaternary alcohol group
D: Numbers 2,3 and 4 are tertiary alcohol groups
E: Numbers 2,3 and 4 are quaternary alcohol groups
88. Which correctly represents hydrogen bond by the dotted line ?
89. Which of the following reaction does not occur ? ( C6H6 = benzene )
90. What is the product of the following reaction ?
91. Cyclopentene is the chief organic product in which reaction ?
92. What is chief product of the following reaction ?
Ni, heat, pressure
CH3－CH2－O－CH2－CH = CH2 ＋ H2
93. What is the product (if any) of the following reaction ?
CH3－CH2－O－CH2－CH3 ＋ NaOH (aq)
94. The molecule, CH3－CH－CH3, could be oxidized to a three carbon
|
OH
A: aldehyde B: ketone C: carboxylic acid D: alkene E: alkane
95. What is the correct order of increasing solubility in cyclohexane for the following series of compounds ?
(with the least soluble to be on the left end)
A: 2＜3＜1 B: 3＜1＜2 C: 1＜2＜3 D: 2＜1＜3 E: 3＜2＜1
96. Hydrogen bond is correctly symbolized by a dotted line in which choice ?
97. What is the product of the following reaction ?
CH3－CH2－O－CH2－CH2－CH3 ＋ KOH
98. Which of the following statements about the chemical properties of benzene is true ?
A: It reacts with nitric acid, in the presence of H2SO4 catalyst, to form nitrobenzene
B: It adds bromine to form 1,2－dibromobenzene
C: Its double bonds are easily attacked by oxidizing agents
D: It adds hydrogen to form 1,3－cyclohexadiene
E: It is easy to saturate
99. Which oxidation(s) may happen ?
100. The following structure belongs to what family of compounds ?
A: a secondary alcohol
B: a phenol
C: a tertiary alcohol
D: an ether
E: a quinone
101. What is one of products in the following reaction ?
H2SO4, t＜140℃
CH3－OH ＋ CH3－CH2－OH
A: CH3－CH2－CH3
B: CH3－O－CH2－CH3
C: CH3－CH2－CH2－OH
D: HO－CH2－CH2－CH2－OH
E: No reaction occurs
102. To change CH3－S－S－CH3 to CH3－SH requires the action of
A: water
B: a reducing agent
C: an acid catalyst
D: an oxidizing agent
E: a sulfonating agent
103. What is the IUPAC name for t－butyl alcohol ?
A: 1,1－dimethylethanol
B: 1,1－dimethyl－1－ethanol
C: 2－methyl－2－propanol
D: 2－methylisopropanol
E: 1,1,1－trimethylmethanol
104. In the first step of the addition of HCl to CH3－CH = CH2 which cation forms ?
105. Which reduction reaction can occur ?
A: 1,2 B: 1,2,3 C: 2,3,4 D: 1,2,4 E: 1,3,4
106. Consider the next pair
CH3－CH2－OH (ethanol) CH3－O－CH3 (Dimethyl ether)
1: They are structural isomers
2: They both form hydrogen bonds in pure state
3: Both readily give substitution reaction
4: Both can be prepared from an alkyl halide
A: 1 B: 1,2 C: 1,3 D: 1,4 E: 1,2,3,4
107. What products can form in the following reaction ?
A: 1 B: 2 C: 2,3 D: 2,3,4 E: 3,4
108. Which statements are true for the following compounds ?
a: CH3NH2 b: (CH3)2NH c: (CH3)3N d: (CH3)4N＋Cl－
1: All are Lewis bases
2: a and c can form acid amides
3: c can be prepared from a with CH3I
4: In pure state they all form hydrogen bonds
A: 1,2,3,4 B: 2,3,4 C: 1,2 D: 3 E: 4
109. Starch and glycogen both are polymers of
A: glucose and fructose
B: glucose
C: glucose－1－phosphate
D: glucose and sucrose
E: glucose and lactose
110. Consider glycogen and cellulose
1: Both are hydrolyzed by the same enzyme
2: Both contain glucose units
3: The monomers of both are held together by glycosidic bonds
4: The main function of both is the storage of chemical energy
A: 1,2 B: 1,3 C: 2,3 D: 1,3,4 E: 1,2,3
111. Which of the next functional groups can be found in carbohydrates ?
1: alcoholic hydroxyl group
2: keto group
3: ester group
4: aldehyde group
A: 1,3 B: 1,2,4 C: 1,2,3 D: 2,3 E: 2,3,4
112. How many optical isomers does the next compound have ?
A: 2 B: 3 C: 6 D: 8 E: 9
113. Which statements are true for enantiomers ?
1: They have the same molecular formula
2: They have the same reactivity for an achiral molecule
3: They have the same reactivity for a chiral molecule
4: They have the same boiling points
A: 1,2 B: 1,2,3 C: 1,2,4 D: 2,3,4 E: 2,3
114. Which statements are true for chiral compounds ?
1: Chirality does not effect reactions with achiral compounds
2: Two enantiomers have the same melting points
3: Enantiomers are constitutional isomers
4: A chiral carbon is in sp3hybrid state
A: 3 B: 4 C: 1,2 D: 1,2,3 E: 1,2,4
115: Glucose is
A: an oligosaccharide
B: an aldohexose
C: an aldopentose
D: a ketohexose
E: a disaccharide
116.Consider the next structure
1: The molecule is sucrose
2: The compound is a nonreducing sugar
3: The molecule consists of a glucose and a galactose unit
4: The reaction that results monomers is condensation
A: 1,2 B: 2,3 C: 3,4 D: 1,4 E: 1,2,3,4
117. The arrangement of sugars into D and L configuration is based upon their resemblance to D or L
A: glyceraldehyde B: glycerol C: glucose D: ribose E: acetalhyde
118. Which of the following amino acids is not optically active ?
A: leucine B: alanine C: asparagine D: serine E: glycine
119. The sulfur containing amino acids are
1: methionine 2: asparagine 3: cysteine 4: arginine
A: 1 B: 2 C: 2,3 D: 1,3 E: 3,4
120. Consider the next peptide
1: The amino-terminal comes from a glycine
2: The carboxyl-terminal comes from a lysine
3: It contains three amino acids
4: It can be also represented as Gly－Ser－Lys
A: 1,2,3 B: 2,3 C: 1,2,3,4 D: 1,2 E: 3
121. Consider the quaternary structure of proteins
1: The structure is stabilized by covalent bonds
2: The structure means the subunit composition
3: The structure is formed by more than one polypeptide chains
4: All proteins have quaternary structure
A: 1 B: 1,2 C: 2,3 D: 3,4 E: 2,4
122. All polypeptide chains contain which elements ?
A: C, H, O, N, S, P
B: C, H, O, N
C: C, H, O, P
D: C, H, O, N, Fe
E: C, H, O, N, S
123. In the double helix of DNA
1: The two chains run in opposite direction
2: The bases are on the outside of the helix
3: The helix is stabilized by the electrostatic interactions between the phosphate groups
4: Adenine is always paired with thymine
A: 1 B: 1,4 C: 3,4 D: 1,2,4 E: 1,3,4
124. In the double helix of DNA
1: The two chains run in parallel direction
2: The phosphate and the deoxyribose units are on the outside of the helix
3: The helix is held together by hydrogen bonds
4: Guanine is always paired with adenine
A: 2,3 B: 1,3 C: 1,4 D: 3,4 E: 1,3,4
125. Which of the following substances are biopolymers ?
1: nucleotides 2: proteins 3: disaccharides 4: phospholipids
A: 1,2 B: 2 C: 2,3 D: 2,4 E: 1,2,3,4
126. Esters are
A: 1,2 B: 2 C: 1,2,4 D: 1,2,3 E: 2,4
127. Amines are
A: 1 B: 1,2 C: 1,2,3 D: 1,3 E: 1,3,4
128. Amide function is present in
A: 1,2 B: 2,3 C: 3,4 D: 1,2,3 E: 2,4
129. Choose the phosphodiester bond
130. Choose the phosphoester bond
131. Which structure contains phosphoanhydride bond ?
132. Choose the structures that contain anhydride bond
A: 1,2 B: 2,3 C: 3,4 D: 1,4 E: 2,4
133. Biopolymers are
1: disaccharides
2: proteins
3: polyethylenes
4: nucleic acids
A: 1,3 B: 2,4 C: 3,4 D: 3 E: 2,3,4
134. Select the correct statements
1: All enzymes are catalysts
2: All catalysts are enzymes
3: Catalysts decrease the activation energy of the catalyzed reaction
4: Catalysts decrease the equilibrium constant of the catalyzed reaction
A: 1,2 B: 2,3 C: 1,3 D: 2,4 E: 2,3,4
135. Neutral fats
1: contain glycerol
2: contain phosphoester bond
3: contain ester bond
4: are found in membranes
A: 1,2 B: 2,3 C: 1,3 D: 2,4 E: 2,3,4
136. Phospholipids contain
1: glycerol
2: ester bond
3: a polar head alcohol
4: phosphoester bond
A: 1,2 B: 2,3 C: 1,3 D: 2,4 E: 1,2,3,4
137. Consider biological membranes
1: Membranes are asymmetrical
2: Phospholipids are the main membrane components
3: Integral proteins are associated to the membranes by covalent bonds
4: The surface of the membranes is always nonpolar
A: 1,2 B: 2,3 C: 1,3 D: 2,4 E: 2