Biology 12 - Biochemistry Practice Exam KEY
Water:
1. The bond between water molecules is a(n)
a. ionic bond
b. covalent bond
c.
polar covalent bond
d. hydrogen bond
2.
The water properties: good solvent, temperature regulator and lubricant all depend on
a. ionic bond
b. covalent bonds
c. peptide bonds
d. hydrogen bonds
3.
The weakest bond below is
a. hydrogen bond
b. peptide bond
4.
c.
covalent bond
d. ionic bond
List 3 special properties of water.
Good temperature regulator – ex. sweat
Good lubricant - in joints of body
Good solvent - dissolves substances ex. blood
Acids, Bases and buffers:
5. Which of the following would be produced during exercise and cause the pH of the body to drop?
a. K
b. Clc. C a
d. H+
6.
A solution becomes more acidic when a chemical is added to it. The chemical added contains
a. sodium ions
b. hydrogen ions
c. hydroxide ions
d. bicarbonate ions
7.
What number below represents a strong acid on the pH scale?
a. 8
b. 10
c. 3
8.
9.
The purpose of buffers is to
a. increase pH
b. neutralize solution
A slightly basic solution has a pH value of
a. 9
b. 6
d. 6
c. absorb all the OH ions d. control pH level
c.
8
d. 3
10. High basicity depends on
a. high OH- ion conc. b. high H+ ion conc.
c. low dissociation level
d. polar bond formation
11. A slightly acid solution has a pH value of
a. 9
b. 6
c.
8
d. 3
12. High acidity depends on
a. high OH- ion conc. b.
c.
low dissociation level
d. polar bond formation
13. Buffers
a. keep pH at 4
high H+ ion conc.
b. add more H+ ions
c. add OH- ions
d.
14. When hydrogen chloride, a strong acid, is added to water, the pH
a. goes up
b. stays the same
c. goes down
remove excess H+ and OH- ions
d.
15.
Acids have a pH that is less than 7, and bases have a pH that is greater than 7 .
16.
At pH = 7, [ H+ ] = [ OH- ]. Below pH 7, which of these is greater?
[ H+ ]
cannot be determined
17.
Which of the following represents the largest [ H+ ] pH = 3, pH = 4, pH = 8, pH = 10
18.
Define:
19.
What is the importance of pH to biological systems?
Extremes in pH cause proteins to denature, they lose their normal shape and may not function.
acid and base
acid - increase [ H+ ], pH less than 7
base - increase [ OH- ], pH greater than 7
Carbohydrates:
20. Maltose is an example of a
a. monosaccharide
b. disaccharide
c.
polysaccharide
d. protein
21. Starch, cellulose and glycogen are all
a. lipids
b. monosaccharides
c.
polysaccharides
d. disaccharides
22. In carbohydrates the ratio of hydrogen to oxygen is usually
a. 6 : 12
b. 2 : 1
c. 1 : 2
d. 3 : 1
23. Which of the following is not a carbohydrate?
a. fructose
b. glucose
d. starch
c.
amino acid
24. When many glucose molecules undergo dehydration synthesis, the result is
a. protein
b. phospholipid
c. polysaccharide
d. polypeptide
25. Glucose is an example of a(n)
a. monosaccharide
b. disaccharide
d. protein
c.
polysaccharide
26. Which of the following is not stored in animal tissues?
a. lipids
b. protein
c. glycogen
d. starch
27. Which of the following is not found in plant tissue?
a. lipids
b. starch
c.
glycogen
d. cellulose
28. Which pair is mismatched?
a. amino acid - protein
c. glucose - starch
glycerol - glycogen
phosphate - nucleotide
29.
b.
d.
Monosaccharides, disaccharides and polysaccharides may be compared as to the number of monosaccharide
(or glucose) molecules they contain.
30. Which of the following represents the building blocks of carbohydrates? B
Proteins:
31. Proteins are polymers of
a. nucleotides
b.
amino acids
c.
fatty acids
32. The groups H - N - H and O = C - OH are both found in
a. lipids
b. polysaccharides
c. amino acids
d. monosaccharides
d. monosaccharides
33. A peptide bond
a. joins fatty acids
c. joins disaccharide sugars
b.
d.
joins monosaccharide sugars
joins amino acids
34. A chain of two amino acids is called a
a. dipeptide
b. diphosphate
c.
dinucleotide
d. disaccharide
35. A peptide bond joins
a. C with O
c.
C with C
d. O with H
b.
C with N
36. Different kinds of amino acids are usually distinguished by the
a. number of carbon atoms present
b. the R groups present
c. how many amino acids are missing
d. whether or not Nitrogen is present
37. The “backbone” of a polypeptide would be composed of
a. the bases
b. sugar-phosphate-sugar-phosphate
c. N - C - C - N - C - C etc.
d. the R groups
38. Which of the following contains the element Nitrogen?
a. fructose
b. glucose
c. amino acid
d. starch
39. A single helix shape of a protein would be described as a
a. primary protein
b. secondary protein c. tertiary protein
d. globular protein
40.
41.
The primary structure of a protein is a polymer of amino acids,
A secondary structures shape can described as bent, and the tertiary structures shape can be described as bent
and folded A quaternary structure contains more than 1 polypeptide.
Draw and label an amino acid: include functional group, amine group, carboxyl acid.
42.
Describe what makes each amino acid different.
R or functional group
43.
Define denaturation.
The change in shape of a protein
44.
State 3 ways that protein may be denatured.
Extremes in pH, extremes temperature, heavy metals
45.
Why is denaturation of protein a problem for organisms?
Proteins lose their shape and may not function
46.
List 4 functions of proteins.
Structural, enzymes, hormones, antibodies, hemoglobin, muscle
47. Which of the following represents the building blocks of proteins? A
Lipids:
48. Fats, phospholipids and steroids are all
a. proteins
b. carbohydrates
49. Glycerol is part of a
a. glycogen molecule b.
c.
lipids
neutral fat molecule c. unsaturated fatty acid
50. A neutral fat is composed of 3
a. glycogen
b. glucose
c.
phospholipids
51. Which molecule is unsaturated? B
52. Double bonds between the carbons indicates a (n)
a. saturated fatty acid
b.
c. neutral fat
d.
unsaturated fatty acid
phospholipid
53.
An unsaturated fatty acid contains less HYDROGEN than a saturated one.
54.
List 3 types of lipids and their functions.
Neutral fat - long term energy storage, insulation, cushioning
Phospholids - form cell membranes
Steroids - hormones and cholesterol
d. steroids
d. saturated fatty acid
d. fatty acids
55. Which of the following represents a neutral fat?
C
Nucleic acids:
56. Why is ATP called the ‘energy currency’ of the cell?
ATP is the energy currency of the cell because it contains high energy bonds - energy is released when these
bonds are broken.
57.
What are 3 differences between DNA and RNA?
DNA
Sugar
deoxyribose
Nitrogenous bases
A,T,C,G
Shape
double helix
Polymers, dehydration synthesis and hydrolysis:
58. Hydrolysis involves the
a. splitting of water
b.
c. joining by adding water
d.
RNA
ribose
A,U,C,G
single helix
splitting by water removal
splitting by adding water
59. Glucose to starch involves
a. hydrolysis
b.
dehydration synthesis
60. Starch to glucose involves
a. hydrolysis
b.
dehydration synthesis
61. Polymers are broken down by
a. dehydration synthesis
b. polymerization
c. oxidation
c.
c.
oxidation
hydrolysis
62. Which of the following can be formed by hydrolysis?
a. neutral fat
b. glycogen
c. cellulose
63. Which of the following best relates to dehydration synthesis?
a. cellulose to starch
b. glucose to glycogen
c. starch to glucose
64. Which of the following best relates to hydrolysis?
a. cellulose to starch b. glucose to glycogen c. starch to glucose
65. Which of the following is a polymer?
a. fructose
b. glucose
c.
amino acid
d. reduction
d. reduction
d. autolysis
d. glucose
d. glycogen to glucose
d. glycogen to amino acids
d. starch
66. Which of the following is not a polymer?
a. neutral fat
b. cellulose
c.
67.
What are the 4 classes of organic polymers?
Carbohydrates, proteins, lipids, nucleic acids
68.
Which polymers are most concerned with energy?
Carbohydrates
69.
Which polymers form enzymes?
Proteins
70.
Which polymers make up chromosomes and genes?
Nucleic acids
71.
Which 2 polymers may form hormones?
Proteins and lipids (steroids)
amino acid
d. starch