LAB FINAL BCHEM Flashcards
(100 cards)
1
Q
1.The parent compound of cholesterol has hexagonal rings:
a. 3
b. 4
c. 5
d. 6
A
a. 3
1 = Pentagonal rings
3 = Hexagonal rings
4 = Total Rings (Cholesterol)
2
Q
2.The parent compound of cholesterol has pentagonal rings:
a. 1
b. 2
c. 3
d. 4
A
a. 1
1 = Pentagonal rings
3 = Hexagonal rings
4 = Total Rings (Cholesterol)
3
Q
3.Which enzyme catalyzes the hydrolysis of the polysaccharide starch to the disaccharide maltose?
A. Catalase
B. Amylase
C. Pepsin
D. Trypsin
A
Amylase
4
Q
- Which are conjugates?
A. weak acid and strong base
B. weak acid and weak base
C. strong acid and strong base
D. none of the above
A
weak acid and weak base
5
Q
- Normal pH of Blood
A. 6.35-6.45
B. 6.45-7.35
C. 7.35-7.45
D. 8.35-8.45
A
7.35-7.45
Gastric Juice = 1.0-3.0
Urine = 4.6- 8.0
Blood = 7.35 - 7.45
6
Q
- Normal pH of Urine
A. 2.6-5.0
B. 4.6 -8.0
C. 5.0-7.6
D. 6.6-9.0
A
4.6 -8.0
Gastric Juice = 1.0-3.0
Urine = 4.6- 8.0
Blood = 7.35 - 7.45
7
Q
7.Normal pH of Gastric juice
A. 1.0-3.0
B. 2.0-5.0
C. 5.0-8.0
D. 6.0-9.0
A
1.0-3.0
Gastric Juice = 1.0-3.0
Urine = 4.6- 8.0
Blood = 7.35 - 7.45
8
Q
8.pH is detected and measured by using either a pH meter, or color-changing acid-base indicators. Acid-base indicators are:
A. strong organic acids
B. strong organic bases
C. weak organic acids
D. weak organic bases
A
weak organic acids
9
Q
- Which are medically important carbohydrates?
A. Pentose
B. Hexose
C. Sedoheptulose
D. Ketose
A
Hexose
10
Q
10.Sugar that is readily metabolized by most tissues:
A. Sucrose
B. Fructose
C. Glucose
D. Lactose
A
Glucose
11
Q
11.A positive result is indicated by the precipitation of silver, producing a characteristic “silver mirror” appearance:
A. Tollen’s test
B. Picric Acid test
C. Benedict’s test
D. Molisch’s test
A
Tollen’s test
A. Tollen’s test = silver mirror
B. Picric Acid test
C. Benedict’s test = brick-red precipitate
D. Molisch’s test = H2SO4 purple-colored
12
Q
12.A positive result is indicated by the color change from clear blue to a brick-red precipitate.
A. Tollen’s test
B. Picric Acid test
C. Benedict’s test
D. Molisch’s test
A
Benedict’s test
A. Tollen’s test = silver mirror
B. Picric Acid test
C. Benedict’s test = brick-red precipitate
D. Molisch’s test = H2SO4 purple-colored
13
Q
13.Colorimetric test for carbohydrates utilizing sulfuric acid to produce a purple-colored compound in positive tests.
A. Tollen’s test
B. Picric Acid test
C. Benedict’s test
D. Molisch’s test
A
Molisch’s test
A. Tollen’s test = silver mirror
B. Picric Acid test
C. Benedict’s test = brick-red precipitate
D. Molisch’s test = H2SO4 purple-colored
14
Q
14.In Barfoed’s Test, a negative result is obtained when:
A. There is formation of reddish precipitate
B. The blue color of the solution is maintained
C. A reddish layer is formed instead of purple
D. The solution becomes black
A
The blue color of the solution is maintained
15
Q
15.Colorimetric tests for glucose are examples of chemical methods that rely on the fact that these substances are____that can react with other components to yield precipitates or colored complexes, which can be quantified.
A. Alkylating agents
B. Tautomers
C. Isomers
D. Reducing agents
A
Reducing agents
16
Q
16.Colorimetric tests for carbohydrates are used in the following, EXCEPT:
A. screening for the presence of carbohydrates in urine
B. identification of the specific carbohydrate
C. detecting carbohydrates in unknown samples
D. determining the concentration of carbohydrates, in some cases
A
identification of the specific carbohydrate
17
Q
17.Enzyme used in glucose determination
A. Glucose oxidase
B. Oxidoreductase
C. Hydroxylase
D. Peroxidase
A
Glucose oxidase
18
Q
18.The most important reactions of sugars are based on the reactivity of their:
A. Alkyl groups
B. Aldehyde groups
C. Carboxyl groups
D. Carbonyl groups
A
Aldehyde groups
19
Q
19.Lipids are classified together because they are fat like substances which are insoluble in water, but
A. soluble in organic solvents
B. soluble in alcohol only
C. melts at the same temperature range
D. mostly liquid in its natural form
A
soluble in organic solvents
20
Q
20.The following are example/s of lipids:
A. Triacylglycerols
B. Cholesterol
C. Arachidonic acid
D. All of the above
E. A & B only
A
All of the above
21
Q
21.Role of lipids in metabolism:
A. Rich energy source
B. Readily utilized as a primary energy source
C. Lipids are utilized through beta-oxidation
D. A and C only
A
A and C only
22
Q
- Why are fatty acids insoluble in water?
A. Due to the amphiphilic properties of fatty acids
B. Due to the large size of the molecule
C. Due to the lightness of the molecule
D. Due to the heaviness of the molecule
A
Due to the amphiphilic properties of fatty acids
23
Q
- What is the predominant configuration of unsaturated fatty acids?
A. Cis-form
B. Trans-form
C. Both A and B
D. None of the above
A
Cis-form
24
Q
24.General test for presence of fats
A. Cooper acetate test
B. Liebermann-Burchard test
C. Acrolein test
D. Tollen’s test
A
Acrolein test
25
25.Cholesterol serves as a precursor of:
A. Steroid hormones
B. Bile acids
C. Vitamin D
D. All of the above
All of the above
26
26.The following are examples of organic solvents, EXCEPT:
A. Ethyl alcohol
B. Distilled water
C. Ether
D. Acetone
Distilled water
27
27.The parent compound of cholesterol has how many rings?
a. 3
b. 4
c. 5
d. 6
b. 4
## Footnote
1 = Pentagonal rings
3 = Hexagonal rings
4 = Total Rings (Cholesterol)
28
28.Proteins are polymers of amino acids that are connected via:
A. Ionic bonds
B. Hydrogen bonds
C. Peptide linkages
D. Covalent bonds
Peptide linkages
29
29.Proteins have a variety of functions, including the following, EXCEPT:
A. Catalysis of biochemical reactions
B. Provide a means to store energy
C. Transport molecular oxygen
D. Serve as structural materials
Provide a means to store energy
30
30.The ultimate reference method for determining concentration of protein is:
A. Colorimetric assay
B. Electron microscopy
C. Analysis of nitrogen content
D. Enzyme analysis
Analysis of nitrogen content
31
31.The following are examples of newer technologies in protein analysis, EXCEPT:
A. Colorimetry
B. Nephelometry
C. ELISA
D. Western blot
Colorimetry
32
32. In the Biuret reaction, a positive result manifests as:
A. Red color
B. Silver color
C. Blue color
D. Pink or violet color
Pink or violet color
## Footnote
Red color = Millon's / Soluble Proteins
Pink or violet color = Biuret / Peptide Bonds
Yellow color = Xantoproteic/ Souble Proteins
Purple color = Ninhydrin/ Ammonia
33
33. The Biuret reaction detects the presence of:
A. Peptide bonds
B. Ammonia
C. Soluble proteins
D. Nitrogen
Peptide bonds
## Footnote
Red color = Millon's / Soluble Proteins
Pink or violet color = Biuret / Peptide Bonds
Yellow color = Xantoproteic/ Souble Proteins
Purple color = Ninhydrin/ Ammonia
34
34.In Millon's reaction, a positive result manifests as:
A. Red color
B. Silver color
C. Blue color
D. Pink or violet color
Red color
## Footnote
Red color = Millon's / Soluble Proteins
Pink or violet color = Biuret / Peptide Bonds
Yellow color = Xantoproteic/ Souble Proteins
Purple color = Ninhydrin/ Ammonia
35
35.Millon's reaction detects the presence of:
A. Peptide bonds
B. Ammonia
C. Soluble proteins
D. Nitrogen
Soluble proteins
## Footnote
Red color = Millon's / Soluble Proteins
Pink or violet color = Biuret / Peptide Bonds
Yellow color = Xantoproteic/ Souble Proteins
Purple color = Ninhydrin/ Ammonia
36
36.In the Xanthoproteic reaction, a positive result manifests as:
A. Red color
B. Yellow color
C. Green color
D. Blue color
Yellow color
## Footnote
Red color = Millon's / Soluble Proteins
Pink or violet color = Biuret / Peptide Bonds
Yellow color = Xantoproteic/ Souble Proteins
Purple color = Ninhydrin/ Ammonia
37
37 .Xanthoproteic reaction detects the presence of:
A. Peptide bonds
B. Ammonia
C. Soluble proteins
D. Nitrogen
Soluble proteins
## Footnote
Red color = Millon's / Soluble Proteins
Pink or violet color = Biuret / Peptide Bonds
Yellow color = Xantoproteic/ Souble Proteins
Purple color = Ninhydrin/ Ammonia
38
38.In the Ninhydrin reaction, a positive result manifests as:
A. Pink color
B. Orange color
C. Purple color
D. Green color
Purple color
## Footnote
Red color = Millon's / Soluble Proteins
Pink or violet color = Biuret / Peptide Bonds
Yellow color = Xantoproteic/ Souble Proteins
Purple color = Ninhydrin/ Ammonia
39
39.Ninhydrin reaction detects the presence of:
A. Peptide bonds
B. Ammonia
C. Soluble proteins
D. Nitrogen
Ammonia
## Footnote
Red color = Millon's / Soluble Proteins
Pink or violet color = Biuret / Peptide Bonds
Yellow color = Xantoproteic/ Souble Proteins
Purple color = Ninhydrin/ Ammonia
40
40.Precipitation that is seen after heating an aqueous solution of protein signifies protein:
A. Breakdown
B. Rearrangement
C. Degradation
D. Denaturation
Denaturation
41
41.Protein structure resulting from folding into a three-dimensional form. This structure controls the basic function of the protein.
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
Tertiary structure
42
42.Protein structure that has regular repeats and is stabilized by hydrogen bonds.
Includes Alpha helix, Beta Sheet and Beta Turns.
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
Secondary structure
43
43.Uses of lecithin include:
A. Emulsifier
B. Surfactant
C. Lubricant
D. All of the above
All of the above
44
44.Enzymes accelerate reactions by the activation energy needed for the reaction:
A. Stopping
B. Raising
C. Lowering
D. Binding
Lowering
45
45. The values for environmental factors at which an enzyme functions best is:
A. Paradigm of maximum effectiveness
B. Optimal conditions
C. Comfortable conditions
D. Efficient conditions
Optimal conditions
46
46.During the procedure using the potato extract what was the enzyme studied?
A. Trypsin
B. Pepsin
C. Catalase
D. Amylase
Catalase
47
47.What happens to an enzyme when it denatures?
A. The activation energy of the reaction is doubled
B. The activation energy of the reaction is lowered
C. Its optimal conditions for temperature of the enzyme are doubled
D. The shape of the enzyme molecule is changed
The shape of the enzyme molecule is changed
48
48.Most enzymes are composed of:
A. Proteins
B. Lipids
C. Carbohydrates
D. Phosphates
Proteins
49
49. How would an extremely low pH (less than 2) denature an enzyme?
A. The extra energy would cause violent movement and collisions until the bonds in the molecule broke, causing the shape to change
B. The high concentration of hydrogen ions would break the bonds in the molecule, causing the shape to change
C. The high concentration of hydroxide ions would break the bonds in the molecule, causing the shape to change
D. Because pH molecules are structurally similar to the substrate molecules, they inhibit the chemical reaction
The high concentration of hydrogen ions would break the bonds in the molecule, causing the shape to change
50
50.How would extremely high temperatures denature an enzyme?
A. The extra energy would cause violent movement and collisions until the bonds in the molecule broke, causing the shape to change
B. The high concentration of hydrogen ions would break the bonds in the molecule, causing the shape to change
C. The high concentration of hydroxide ions would break the bonds in the molecule, causing the shape to change
D. Because pH molecules are structurally similar to the substrate molecules, they inhibit the chemical reaction
The extra energy would cause violent movement and collisions until the bonds in the molecule broke, causing the shape to change
51
51.How do inhibitors affect the reaction rate of enzymes?
A. The extra energy would cause violent movement and collisions until the bonds in the molecule broke, causing the shape to change
B. The high concentration of hydrogen ions would break the bonds in the molecule, causing the shape to change
C. The high concentration of hydroxide ions would break the bonds in the molecule, causing the shape to change
D. Because inhibitor molecules are structurally similar to the substrate molecules, they inhibit the chemical reaction
Because inhibitor molecules are structurally similar to the substrate molecules, they inhibit the chemical reaction
52
52.Which isotype of creatine phosphokinase is elevated in cases of subarachnoid hemorrhage?
A. CPK MB
B. CPK MM
C. СРК BB
D. None of the above
СРК BB
53
53.Both Buret test and Benedicts test reveal a solution which is blue in color. What do the results tell you?
A. The solution is negative for proteins
B. The solution is negative for simple sugars
C. The solution may be a lipid
D. All of the above
All of the above
54
54. What gives Biuret reagent its characteristic blue color?
A. Potassium hydroxide
B. Cu+2
C. Potassium sodium tartrate
D. Protein
Cu+2
55
55.What does a pink biuret test result indicate?
A. Absence of amino acids
B. Presence of polypeptides
C. Presence of short-chain peptides
D. None of the above
Presence of short-chain peptides
56
56.Biuret solution tests for the presence of molecules made when amino acids have been joined together by peptide bonds:
A. True
B. False
TRUE
57
57.Which of the following statements is true regarding the solubility of nucleic acids:
A. They are insoluble in alcohol
B. They are slightly soluble in cold water
C. They are readily soluble in hot water
D. All of the above
All of the above
58
58. Which of the following is a constituent of nucleic acids?
A. Carbon
B. Phosphorus
C. Hydrogen
D. All of the above
All of the above
59
59.The product of complete hydrolysis of deoxyribonucleic acid will yield:
A. Uracil
B. Cytosine
C. Guanine
D. A and C only
Cytosine
60
60. The product of complete hydrolysis of ribonucleic acid will yield:
A. Uracil
B. Cytosine
C. Guanine
D. All of the above
All of the above
61
61.The glycosidic bonds in DNA and RNA:
A. Connect the sugar to the base
B. Can be hydrolyzed by OH ion
C. Stabilize Watson-Crick H bonds
D. Are free to rotate over about 1800
Connect the sugar to the base
62
62.What are triglycerides composed of?
A. Glycerol
B. 3 fatty acids
C. 2 fatty acids
D. A and B only
A and B only
63
63.Which fatty acids have double bonds?
A. Saturated
B. Unsaturated
C. Both
D. None
Saturated
64
64. Which of the following are reduced coenzymes?
A. NADH and FADH2
B. NAD+ and FAD
C. ATP and GTP
D. Coenzyme A and ubiquinone
NADH and FADH2
65
65.The term pH describes the of the hydrogen ion concentration of the solution.
A. +log
B. sum total
C. reciprocal
D. product
reciprocal
66
66.High pH values therefore correspond to:
A. Low concentrations of H+
B. High concentrations of H+
C. Low concentrations of OH-
D. High concentrations of OH-
Low concentrations of H+
67
67.Proton acceptors
A. Acids
B. Bases
C. Conjugates
D. None of the above
Bases
68
68.Proton donors:
A. Acids
B. Bases
C. Conjugates
D. None of the above
Acids
69
69.Predicts the behavior of weak acids and buffers:
A. Henderson-Hasselbalch equation
B. Bronsted-Lowry theory
C. Arrhenius theory
D. Lewis theory
Henderson-Hasselbalch equation
70
70.Components in the blood responsible for maintaining pH.
A. Carbonates
B. Proteins
C. Phosphates
D. All of the above
All of the above
71
71.Bronsted acids are represented as:
A. Hln
B. H+
C. pKa
D. HA
HA
72
72.What describes the relative strength of both acids and bases?
A. pH
B. pKa
C. log
D. -log
pKa
73
73.Completely dissociates at high pH
A. Strong bases
B. Weak bases
C. Strong acids
D. Weak acids
Strong bases
74
74.The ability to resist a change in pH following addition of strong acid or base
A. Neutralization
B. Buffering
C. Steady state
D. Dilution
Buffering
75
75.pH is detected and measured by using either a pH meter, or color-changing acid-base indicators. Acid-base indicators are:
A. strong organic acids
B. strong organic bases
C. weak organic acids
D. weak organic bases
weak organic acids
76
76.A catabolic enzyme:
A. Joins two or more substances into a larger molecule
B. Cleaves a molecule into two or more parts
C. Inserts a substance between two or more existing molecules
D. Acts as a chemical messenger between amino cells
Cleaves a molecule into two or more parts
77
77.An anabolic enzyme:
A. Cleaves a molecule into two or more parts
B. Inserts a substance between two or more existing molecules
C. Joins two or more substances into a larger molecule
D. Acts as a chemical messenger between amino cells
Joins two or more substances into a larger molecule
78
78.An allosteric enzyme has which of the following properties?
A. It can only operate in an acidic environment,
B. It can only operate in an alkaline environment,
C. It becomes active only when it binds with a specific cofactor,
D. It can function either as a catabolic or anabolic enzyme.
It becomes active only when it binds with a specific cofactor,
79
79. A proteolytic enzyme has the following action:
A. It cleaves complex sugars into simple sugars.
B. It joins fatty acids into proteins
C. It joins proteins to sugars to form glycoproteins.
D. It cleaves protein molecules into smaller units.
It cleaves protein molecules into smaller units.
80
80 .Amylase has all of the following properties except:
A. It breaks down starches into sugars.
B. It cleaves proteins into amino acids.
C. It is a component of human saliva.
D. High serum levels may indicate pancreatic inflammation.
It cleaves proteins into amino acids.
81
81.The function of a protein is determined primarily by:
A. Its molecular weight
B. The number of amino acids it contains
C. Its spatial conformation
D. Its affinity for hydrocarbons
Its spatial conformation
82
82.Which of the following is not involved in the biosynthesis of a protein molecule?
A. Codon
B. Ribosome
C. Messenger RNA
D. Amylase
Amylase
83
83.Protein catabolism can yield which of the following:
A. Complex carbohydrates
B. Glucose
C. Free fatty acids
D. Omega-3 fatty acids
Glucose
84
84. The primary function of the Citric Acid Cycle is to:
A. Facilitate aerobic cellular energy production
B. Oxidize cellular toxins
C. Produce anaerobic energy by fermentation
D. Synthesize vitamin D
Facilitate aerobic cellular energy production
85
85.Which of the following is a free fatty acid?
A. Eicosapentaenoic acid
B. Citric acid
C. Cholesterol
D. Glycerol
Eicosapentaenoic acid
86
86. Fatty acids are esterified into mono-, di-, or triglycerides by attaching to:
A. Sterol
B. Cholesterol
C. Glycerol
D. Sodium chloride
Glycerol
87
87.Omega-3 fatty acids have which of the following?
A. At least 3 double bonds
B. A 3-carbon backbone
C. A double bond 3 carbons from the end of the chain
D. At least 3 fatty acid molecules linked by omega bonds
A double bond 3 carbons from the end of the chain
88
88. Test for glucose that reflects on how the body metabolizes glucose after ingestion of carbohydrate-rich food.
A. Stimulatory tests
B. Fasting tests
C. Enzymatic tests
D. Radioassay
Stimulatory tests
89
89.Example of stimulatory tests for glucose?
A. Postprandial blood sugar
B. Oral glucose tolerance test
C. Both A and B
D. None of the above
Both A and B
90
90.Method of glucose determination that is dependent on the reducing properties of the sugar:
A. Chemical method
B. Enzymatic method
C. Stimulatory method
D. Metabolic method
Chemical method
91
91.Method of glucose determination that lacks specificity
A. Chemical method
B. Enzymatic method
C. Stimulatory method
D. Metabolic method
Chemical method
92
92.Method of glucose determination that is highly specific
A. Chemical method
B. Enzymatic method
C. Stimulatory method
D. Metabolic method
Enzymatic method
93
93.The cleansing action of detergents is possible because of:
A. Ability of detergents to form bubbles
B. Amphiphilic properties of detergents
C. Biocidal properties of detergents
D. Solubility of detergents in water
Amphiphilic properties of detergents
94
94. Nucleic acids can be analyzed experimentally by their:
A. Molecular weight
B. Absorption of visible light
C. Absorption of UV light
D. None of these
Absorption of UV light
95
95.A purine with an amine group on the 6th carbon:
A. Adenine
B. Thymine
C. Uracil
D. Guanine
Adenine
96
96.Principle behind the test for the presence of purines with AgNO3:
A. Hydrolysis between hydrogen bonds of bases
B. Hydrolysis of phosphate-sugar backbone
C. Hydrolysis of N-3 glucosidic bonds between bases and sugar
D. All of the above
All of the above
97
97.A patient with a history of diabetes mellitus is in her 2nd post operative day following a cholecystectomy. She complains of nausea and isn't taking solid food. She becomes shaky and confused. What is the most likely explanation of her symptoms?
A. Anesthesia reaction
B. Hyperglycemia
C. Hypoglycemia
D. Diabetic ketoacidosis
Hypoglycemia
98
98.Main function of insulin hormone?
A. Increase glycogen in the liver
B. Decrease glycogen in the liver
C. Increase blood sugar
D. Decrease blood sugar
Decrease blood sugar
99
99.Acyl carrier protein (ACP) plays an important role in the biosynthesis of:
A. Fatty acids
B. Amino acids
C. Carbohydrates
D. Sugars
Fatty acids
100
100. Vitamins are essential because the organism
A. Can't synthesize the compounds at all
B. Can partially synthesize the compounds
C. Can't synthesize the compounds in adequate amounts
D. None of the above
Can't synthesize the compounds at all
