Biochem Practice Test
1. If you remove all of the functional groups from an organic molecule so that it has only carbon and hydrogen atoms, the molecule becomes a:
A)CarbohydrateB) CarboxylC) CarbonylD) Hydrocarbon
2. Nucleic acids are chains of 5-carbon sugars linked by PHOSPHODIESTER bonds with an organic base protruding from each sugar.
3. Triglycerol contains 3 fatty acids linked by a GLYCEROL molecule.
4. The general term for a large molecule made up of many similar subunits is
A)PolymerB) Functional GroupC) HelixD) Peptide
5. In a DNA molecule, what holds together nitrogenous bases from the two polymer chains (double-sided)?
A)Phosphodiester bondsC) Hydrogen bonds
B)Peptide bondsD) Ionic bonds
6. Which element occurs in nucleic acids?
B)CalciumB) SulfurC) IronD) Phosphorous
7. Which of the following are not found in a nucleotide?
A)CalciumB) SulfurC) IronD) Phosphorous
8. How many hydrogen atoms can be attached to carbon A?3
9. Carbon B?1
10. These molecules are
A)Structural isomersC) ATP molecules
B)Geometric (cis-tran) isomersD) Enantiomers
11. Which of these functional groups behaves as an acid?F
12. Which of these functional groups behaves like a ketone?C
13. Which of these is a hydroxyl group?D
14. Which of these functional groups behaves as a base? A
15. Which of these is a carboxyl group?F
16. Which of these functional groups is characteristic of an alcohol?D
17. Which of these is a phosphate group?B
18. Which action could produce a carbonyl group?
A) the replacement of the –OH of a carboxyl group with hydrogen
B) the addition of a thiol to a phosphate
C) the addition of a hydroxyl to a phosphate
D) the replacement of the nitrogen of an amine with oxygen
19. The sequence of amino acids is the ______structure of proteins.
A) primaryB) secondaryC) tertiary D) quaternary
20. Each water molecule is joined to 4 other water molecules by HYDROGEN bonds.
21. The unequal sharing of electrons within a water molecule makes the molecule POLAR
22. The tendency of an atom to pull electrons towards itself is referred to as its ELECTRONEGATIVE
23. Which are not macromolecules?
A) proteinsB) polysaccharidesC) lipidsD) nucleotides
24. Which of the following is composed of a 1:2:1 ratio of carbon to hydrogen to oxygen?
A) proteinsB) nucleic acidsC) lipidsD) carbohydrates
25. Glucose and fructose are different
A) in the # of carbons they possess.
B) in their relationship to the sucrose molecules.
C) in the way that their atoms are arranged.
D) in the # of double bonds the possess.
26. Oils are
A) liquid at room temperatures.C) found only in animals.
B) saturated fats.D) complex carbohydrates.
27. Which of the following is not part of every nucleotide?
A) RiboseB) Phosphate groupC) BaseD) Pentamer Sugar
28. Glucose dissolves in water because
A) it ionizes.B) is a polysaccharide.
C) is polar and forms many hydrogen bonds with the water molecules.
D) has a very reactive primary structure.
29. Carbon forms how many bonds with other atoms? 4
30. Hydrophobic interactions are exhibited by
A) ionsB) nonpolar moleculesC) polar moleculesD) hydration shells
31. The chemical properties of an atom are primarily dependent by the number of
A) neutrons it has in its nucleusD) energy levels it has
B) isotopes it formsE) electrons it has in its outer shell
C) protons it has in its nucleus
32. Dehydration and hydrolysis reactions involve removing or adding ______to macromolecule subunits.
A) C and OC) C and HE) OH and H
B) CH and NH2D) COOH and H
33. Animals store glucose in the form of GLYCOGEN
34. What bonds maintains the secondary structure of a protein?
A) ionicB) phosphdiesterC) hydrogenD) peptide
35. Which of the following would yield the most energy per gram when oxidized?
A) proteinsB) nucleic acidsC) lipidsD) carbohydrates
36. Nucleotides have a nitrogenous based attached to a sugar at the:
A) 1’ CB) 2’ CC) 3’ CD) 4’ CE) 5’ C
37. The bonding of two amino acid molecules to form a larger molecule requires what? WATER to form the peptide bond
38. Hydrophilic substances are ______whereas hydrophobic substances are ______.
A) water-loving; water-fearingC) soluble in water; soluble in lipid
B) polar; non-polarD) a and b are correct
39. In the formation of a macromolecule, what type of bond would join two amino acids?
A) ionicB) phosphdiesterC) hydrogenD) peptide
40. A triglyceride contains fatty acids and
A) glucoseB) glycogenC) glycerolD) an amino acid
41. The globular shape of the protein is which level of structure?
A) primaryB) secondaryC) tertiaryD) quaternary
42. What type of macromolecule carries out catalysts in biological systems?
A) proteins called enzymesC) nucleic acids called DNA
B) carbohydrates called starchesD) carbohydrates called sugars
43. In the formation of a macromolecule, what type of reaction would join 2 monomers together?
A) hydrophobic reactionC) dehydration reaction
B) hydrolysis reactionD) denaturation reaction
44. The secondary structure of a polypeptide is primarily determined by which of the following?
(A) Hydrogen bonding (B) The number of amino acids (C) NADH (D) Golgi apparatus (E) Ribosomes
45. Hydrogen bonds occur
(A) between nonpolar substances
(B) between adenine and thymine
(C) between phosphate and deoxyribose in DNA
(D) when a hydrogen and an oxygen in a water molecule share electrons
(E) between carbon and hydrogen in a molecule of methane
46. Which of the following statements is/are true with regard to a polymer of 8 glucose molecules?
I. The chemical formula is C48H96O48
II. The chemical formula is C48H80O40
III. The monomers of glucose were joined via hydrolysis
IV. The monomers of glucose were joined via dehydration synthesis
(A) I only (B) II only (C) IV only (D) I and III only (E) II and IV only
47. Which of the following statements regarding lipids is most accurate?
(A) Lipids are synthesized by ribosomes.
(B) The empirical formula for lipids is typically C1H2O1.
(C) Saturated fats tend to be solid at room temperature because of polar hydrocarbon chains.
(D) Saturated fats tend to be liquid at room temperature due to hydrogen bonding.
(E) Polyunsaturated fats tend to be liquid at room temperature due to numerous double bonds in the hydrocarbon chains.
48. The insolubility of fats in water is due primarily to
(A) the many nonpolar C-H bonds
(B) the ester linkage between a hydroxyl group and a carboxyl group
(C) the presence of glycerol in the structure makeup
(D) the variety of fatty acids in a fat molecule
(E) the large number of double bonds between carbon atoms
49. Lipids with four fused carbon rings and various functional groups attached are known as
(A) phospholipids (B) saturated fats (C) steroids (D) fatty acids (E) chitin
50. A polymer of glucose that serves as a storage macromolecule in animals is
(A) chitin (B) starch (C) glycogen (D) cellulose (E) amylase
51. Storage of fat by the body is advantageous primarily because fats
(A) are insoluble and chemically stable
(B) yield, gram for gram, more than twice as much energy as complex carbohydrates
(C) can be digested with less energy and fewer enzymes than carbohydrates and proteins
(D) store almost all potential energy in chemical bonds
(E) are much easier to produce from surplus molecules that have been broken down by digestive enzymes
52. Cholesterol is important in the metabolism of living things because it can be changed into important compounds that include all of the following EXCEPT
(A) Vitamin D (B) bile salts (C) estrogen (D) keratin (E) testosterone
Keratin is a protein and the rest are derivatives of cholesterol.
53. Which molecule has a carbonyl functional group in the form of a ketone? C
54. The twenty common amino acids differ from each other in the composition of a covalently bonded side chain known as a(n)
(A) polypeptide (B) dipeptide (C) R group (D) amino group (E) carboxyl group
Use the pictures below to answer the next 7 questions.
Which molecule…
55. can be modified and used as the fundamental component of a cell membrane: E because it is a fat and the cell membrane is composed of a lipid called a phospholipid
56. is the building block of both hemoglobin and chlorophyll: C because it’s an amino acid and hemoglobin and chlorophyll are both proteins
57. is responsible for providing energy for nearly all endergonic reactions in the human body: B because it is glucose
58. a carbohydrate utilized in the synthesis of polymers of DNA: A because it is a pentose sugar
59. acts as an acid: C, BUT it is really a neutral molecule since it only has one each COOH and NH2
60. is unsaturated: E because its hydrocarbon chains are kinky and flowy (liquid)
61. is a pentose: A
Characteristics of macromolecules: choose NA, L, C, or P – answers next to characteristic below
62. Double helix NA
63. 4 complex levels of structure P
64. Monomer = monosaccharides C
65. Peptide bonds P
66. Not really a polymer L
67. Contains 3 fatty acids and a glycerol L
68. Monomer = amino acids P
69. Monomer = nucleotides NA
70. DNA and RNA NA
71. Phosphodiester bonds NA
72. N-terminus and C-terminus P
73. –ose C
74. Ester linkages L
75. 1:2:1 ratio of C:H:O C
76. Cholesterol, phospholipids, triglycerides, steroids L
77. 5’ and 3’ endsNA
Starch is a polymer of ALPHA glucose monomers with bonds between 1’ and 4’ carbons.
Cellulose is a polymer of BETA glucose monomers with bonds between 1’ and 4’ (and 1’ and 6’) carbons.
Both are POLYSACCHARIDES formed by DEHYDRATION SYNTHESIS with
GLYCOSIDIC BONDS linking the monomers. Which cannot be broken down by animals? Cellulose Why not?
All the animals that can digest cellulose (like cows and termites) have to do it with the help of symbiotic microbes that produce enzymes that break down the cellulose. This is surprising, yes, because cellulose is just an isomer of starch that has the glucose monomers in a slightly different configuration. Cellulose is one of the most abundant biochemicals in the world, has a huge amount of energy in it. HOWEVER, animals do not make the protein/enzyme needed to break down this organic molecule. This enzyme is called CELLULASE!
- another practice test