Tophat Questions Flashcards
(110 cards)
1
Q
Certain amino acids are nutritionally essential, and so are vitamins. In what way(s) do they differ?
A. The amino acids are chemically similar to each other, the vitamin are chemically diverse.
B. The daily requirement for amino acids is in the order of grams; the requirement for vitamins is milligrams or less.
C. Amino acids are organic compounds, vitamins are mineral
D. Only two of A, B, and C are correct
A
D. Only two of A, B and C are correct
-A is wrong
2
Q
Which of the following statements describe(s) vitamins
A. Vitamins are essential nutrients
B. Daily requirement for a typical vitamin is around 1 gram
C. Vitamins are inorganic substances
D. All of A, B and C are correct
E. Only two of A, B and C are correct
A
A. Vitamins are essential nutrients
3
Q
A healthy child of seven years is eating a balanced diet that includes adequate amounts of all essential nutrients. It supplies 12 grams of nitrogen per day. How much nitrogen is she excreting per day?
A. 12 grams
B. More than 12 grams
C. Less than 12 grams
D. The amount of nitrogen cannot be exerted can not be determined without
Further investigation
A
C. Less than 12 grams
-Positive nitrogen balance means less nitrogen is excreted than ingested. There is a net build-up of protein. Happens while still growing, pregnant, exercising, building muscle.
4
Q
Negative nitrogen balance
a. Can result when the diet is deficient in protein
b. Means that the amount of nitrogen in urine and feces is less than that in the diet
c. Both A and B
d. Neither A nor B
A
A. Can result when the diet is deficient in protein
-More nitrogen excreted than ingested
5
Q
A man of 100kg wants to lose weight. He therefore starts an exercise program that consumes an additional 90 kcal per day, but does not change his diet. How much weight can he expect to lose in 30 days?
A. 9 g B. 30 g C. 90 g D. 300 g E. 900 g
A
D. 300 g
100 kg x 90=9000
9000/30 days=300
6
Q
A female student is maintaining a constant weight of 62 kg by eating a diet that supplies 2000kcal/day. Approximately how much of her energy is devoted to basal metabolic rate (BMR)?
A. 33% B. 50% C. 67% D. 75% E. 90%
A
C. 67% BMR times kcal/day 0.9 x 2000= 1800 1800/62 (weight)= 29.032 29.032 x 2.3 (pounds per kilogram) = 66.77
7
Q
We use macronutrient conversion factors (kcal/g) used to calculate energy intake. For carbohydrate, fat and protein, these are:
A. 4, 4 ,9 B. 4, 9, 4 C. 4, 9, 7 D. 4, 7, 9 E. 4, 7, 4
A
B. 4, 9, 4
8
Q
What essential nutrient is given to chronic alcoholics intravenously in the event the patient requires emergency medical care due to malnutrition A. Tryptophan B. Thiamine C. Threonine D. All of E. Only two
A
B. Thiamine
9
Q
Solutions to be infused for total parental nutrition (TPN) contain A. Proteins B. Glucose C. Fats D. All of E. Only two of
A
E. Only two of
-Not glucose
10
Q
In what ways does a solution for total parental nutrition (TPN) differ from one for naso-gastric feeding (fats= emulsified fatty acids)
A. TPN solutions contain amino acids, naso-gastric solutions contain proteins
B. TPN solutions contain no fats; naso gastric solutions contain fats
C. TPN solutions contain vitamins; naso gastric solutions contain no vitamins
D. All of
E. Only two of
A
A. TPN solutions contain amino acids, naso-gastric solutions contain proteins
11
Q
Amino acids are the building blocks of proteins. Which of the following is true?
A. All amino acids have a similar structure
B. All of amino acids have a charged R group
C. All of amino acids are joined by disulfide bridges
D. All of
E. Only two of
A
A. All amino acids have a similar structure
12
Q
When a protein is denatured A. Its nutrition value is destroyed B. Its biological activity is lost C. It usually becomes more soluble to water D. All of
A
B. Its biological activity is lost
13
Q
Which of the following aspects of protein structure is/are most easily disrupted when a protein is heated in neutral solution A. Peptide linkages B. Disulfide bridges C. Hydrogen bonds D. All of E. None of
A
C. Hydrogen bonds
14
Q
Which of the following treatments will break disulphide bridges in proteins
A. Heating at 100 at pH of 7
B. Heating at 100 in 6M HCl
C. Incubation with the pancreatic protease, trypsin
D. All of
E. None of
A
E. None of the above
-Disulphide bridges are not easily broken. The treatments that break peptide linkages leave disulphide bridges intact
15
Q
When protein is heated at 100 in neutral solution, the effects is/are
A. Breakage of peptide linkages
B. Loss of nutritional value
C. Loss of biological function (ex: catalysis)
D. All of
E. Only two of
A
C. Loss of biological function (ex: catalysis)
16
Q
Which of the following statements about normal hemoglobin (hemoglobin A) is/are correct:
A. The hemoglobin molecule consists of four identical subunits
B. When a hemoglobin molecule binds one molecule of oxygen, its affinity for binding more oxygen is decreased
C. The iron of hemoglobin remains in the Fe2 state in the course of its normally functioning
D. All of
E. Only two of
A
C. The iron of hemoglobin remains in the Fe2 state in the course of its normally functioning
17
Q
The binding of oxygen to hemoglobin is described as cooperative. This means that
A. The affinity of hemoglobin for oxygen becomes greater as the PH. is lowered
B. The shape of the oxygen dissociation curve of hemoglobin is sigmoid
C. In presence of 2,3-bisphologycerate, the affinity of hemoglobin for oxygen is increased
D. Hemoglobin becomes a weaker acid when it is oxygenated
E. Hemoglobin is an effective buffer, participating in the control of the PH. of body fluids
A
B. The shape of the oxygen dissociation curve of hemoglobin is sigmoid
18
Q
Which of the following statements about hemoglobin is/are correct?
A. Oxygenated hemoglobin is a stronger acid that deoxygenated hemoglobin
B. As PH is lowered, the affinity of hemoglobin for oxygen becomes less
C. Each molecule of hemoglobin can combine with four molecules of oxygen
D. All of
E. Only two of
A
D. All of the above
19
Q
What does the right shift in the hemoglobin oxygen dissociation curve signify?
A. Improved oxygen delivery to tissues
B. Improved oxygen extraction in the lungs
C. Response of hemoglobin to increased pH
D. Response to hemoglobin to decreased BPG
A
A. Improved oxygen delivery to tissues
20
Q
Hemoglobin A1C is the product of the non-catalyzed reaction of the hemoglobin with glucose. Under what circumstances will the proportion of hemoglobin A1C be higher than normal?
A. Immediately after a carbohydrate-rich meal
B. After an overnight fast
C. In a diabetic patient with poor control of blood glucose
D. After a strenuous athletic event
E. In a person with a genetic variant of hemoglobin
A
C. In a diabetic patient with poor control of blood glucose
21
Q
Match the description to the the kind of catalyst
Can change the equilibrium constant of a reaction?
A. Enzymes
B. Non-enzyme catalysts
C. Both A and B
D. Neither A nor B
A
D. Neither A nor B
22
Q
Match the description to the the kind of catalyst
Can become saturated if the concentration of reactants is very high?
A. Enzymes
B. Non-enzyme catalysts
C. Both A and B
D. Neither A nor B
A
A. Enzymes
23
Q
Which of the following statements about enzymes is/are correct?
a. Enzymes can make reactions go faster than they would without enzymes
b. Enzymes can make reactions go further than they would without enzymes
c. Enzymes can make reactions go in the opposite direction than they would without enzymes
d. All of
e. Only two of
A
A. Enzymes can make reactions go faster than they would without enzymes
24
Q
Which of the following statements about Km of an enzyme is correct?
a. Km is equal to the velocity of the reaction when the substrate concentration is half that required for saturation
b. When the substance concentration is equal to twice Km the enzyme is saturated
c. Km is equal to hold the time need to reach equilibrium
d. The greater value of Km the faster the enzyme catalyzed reaction will go
e. None of the above statements is correct
A
E. None of the above statements is correct
25
In the following question, match the lettered descriptions to the term:
Enzyme repression:
A. Less enzyme made
B. The catalytic efficiency of existing enzyme is lowered
C. Both A and B
D. Neither A nor B
A. Less enzyme is made
26
In the following question, match the lettered descriptions to the term:
Enzyme inhibition:
A. Less enzyme made
B. The catalytic efficiency of existing enzyme is lowered
C. Both A and B
D. Neither A nor B
B. The catalytic efficiency of existing enzyme is lowered
27
In the following question, match the descriptions to the kind of enzyme inhibitor:
A substance whose structure resembles the substrate of the enzyme:
A. Competitive inhibitor
B. non- competitive inhibitor
C. Allosteric inhibitor
D. None of the above
A. A competitive inhibitor
28
In the following question, match the descriptions to the kind of enzyme inhibitor:
The end product of the metabolic pathway in which the enzyme operates:
A. Competitive inhibitor
B. non- competitive inhibitor
C. Allosteric inhibitor
D. None of the above
C. Allosteric inhibitor
29
Clinical chemistry laboratories often measure the concentration of an enzyme in a patient’s serum. The result of such a measurement can tell a physician:
A. The equilibrium constant of the enzyme catalyzed reaction
B. The substance and products of the enzyme catalyzed reaction
C. The extent of damage in the tissue in which the enzyme is normally present
D. The rate of operation of the metabolic pathway in which the enzyme operates
E. All of
C. The extent of damage in the tissue in which the enzyme is normally present
30
The activity of the enzyme, alkaline phosphatase is increased in the blood of patients with a bone fracture because:
A. The natural substance of the enzyme is more abundant in the blood of these patients
B. The cells of the bone that contain this enzyme have been damaged and release it into the blood
C. The rate of destruction of this enzyme is decreased in these patients
D. A natural inhibitor of this enzyme
E. All of
B. The cells of the bone that contain this enzyme have been damaged and release it into the blood
31
```
Hepatitis B vaccine
A. Can prevent a person from contracting hepatitis B but not A
B. Consists of immunglobin G (IgG)
C. Both of A and B
D. Neither of A and B
```
A. Can prevent a person from contracting hepatitis B but not A
32
Which of the following information transfer processes has NEVER been observed?
A. DNA-RNA
B. RNA-DNA
C. RNA-RNA
D. PROTEIN-RNA
E. All of the above processes have been shown to occur
A. Protein-RNA
33
In what ways do/does a monoclonal antibody differ from a polyclonal antibody?
A. A mono antibody consists of gamma globulin only, a poly antibody consists of several different kinds of globulins
B. A mono antibody is produced in response to the injection of a single antigen, a poly antibody is produced when several antigens are injected
C. A mono antibody interacts with a single epitope; a poly antibody interacts with several different epitopes.
D. All of
E. Only two
C. A mono antibody interacts with a single epitope; a poly antibody interacts with several different epitopes
34
Which of the following treatments can break peptide bonds in a protein?
A. Incubating with digestive enzymes
B. Heating at 110 in 6M hydrochloric acid
C. Exposure to a strong reducing agent such as thioglycolate
D. All of
E. Only two of
E. Only two of
35
Dietary lack of vitamin C (ascorbic acid) results in impaired synthesis of
a. Collagen
b. Elastin
c. Keratin
d. Dna
e. RNA
A. Collagen
36
In the following question match the description to the names of the proteins
Collagen
A. This protein is the main constituent of hair
B. The shape of the molecules of this protein is spherical
C. Synthesis of this protein is impaired in people with vitamin C deficiency
D. This protein cannot be broken down by treatment with acid or enzymes
E. This protein is not described by an of the statements
C. Synthesis of this protein is impaired in people with vitamin C deficiency
37
In the following question match the description to the names of the proteins
Keratin
A. This protein is the main constituent of hair
B. The shape of the molecules of this protein is spherical
C. Synthesis of this protein is impaired in people with vitamin C deficiency
D. This protein cannot be broken down by treatment with acid or enzymes
E. This protein is not described by an of the statements
A. This protein is the main constituent of hair
38
Although all of our cells contain the same DNA sequences, the kinds of proteins made differ from one end of cell to another. These differences result from the fact that
A. All of the DNA is transcribed in every cell, but some of the transcripts are selectively destroyed
B. All of the DNA is transcribed in every cell but only some of the transcripts are translated
C. Only some of the DNA is transcribed in each cell
D. All of the DNA is transcribed and all of the transcripts are translated in every cell, but some of the translation products are selectively destroyed
C. Only some of the DNA is transcribed in each cell
39
```
Which of the following substance is/are constituent of DNA?
A. Thymine
B. Adenine
C. Cytosine
D. All of
E. Only two of
```
D. All of
40
10. A person who has been vaccinated with cowpox (vaccina) becomes immune to smallpox (variola) because
a. The antigens of the vaccine and variola viruses are very similar
b. A persistent low grade infection with vaccinia virus prevents the variola virus from becoming established
c. Development of antibodies against the vaccina virus prevents antibodies against the variola virus from being made
d. Since the vaccine virus contains DNA and the variola virus contains RNA, the two cannot exist together
e. Cells infected with vaccine virus release an enzyme which destroys the variola virus
A. The antigens of the vaccine and variola viruses are very similar
41
Which of the following kinds of RNA is/are made by copying DNA?
a. Ribosomal RNA
b. Transfer RNA
c. Both A and B
d. Neither A nor B
C. Both A and B
42
In what stage of the cell cycle are the cells of a tissue when cell division does not occur?
A. G1
B. S
C. G2
D. M
E. The cells are in various different stages
A. G1
43
In what ways does DNA polymerase differ from RNA polymerase?
a. Dna polymerase requires a DNA template, RNA polymerase an RNA template
b. DNA polymerase requires a template, RNA does not
c. DNA polymerase requires a primer, RNA does not
d. DNA polymerase catalyzes the addition of nucleotides to a 3end, RNA polymerase to a 5end
e. DNA polymerase is a protein, RNA is not
C. DNA polymerase requires a primer, RNA does not
44
Which of the following statements about the genetic code is/are correct?
A. There is only one kind of signal for the “stop translating here”
B. There is only one kind of signal for “start translating here”
C. A triplet of bases can have only one meaning
D. All of
E. Two of
E. Two of
45
Which of the following statements correctly describe(s) a typical mammalian messenger RNA?
A. Messenger RNA has a cap at its 5end
B. Messenger RNA has a polyA tail at its 3end
C. Messenger RNA contains sections that are not translated
D. All of
E. Two of
D. All of
46
The statement that DNA replication is discontinuous means that
A. During much of the cell cycle in eukaryotes, DNA synthesis is not occurring
B. The double stranded products of replication consists of one parental and one newly synthesized strand
C. Replication of one of the two strands of DNA is repeatedly restarted and the products are joined to make the final product
D. All of
E. Only two of
C. Replication of one of the two strands of DNA is repeatedly restarted and the products are joined to make the final product
47
The fungal toxin, a-amantiti inhibits eukaryotic RNA polymerase II. What will be the result when a person eats mushrooms containing a-amanitin?
A. Production of ribosomal RNA stops
B. Production of messenger RNA stops
C. Production of transfer RNA stops
D. Translation of genetic messages stop
E. All of the results in ABCD will happen
B. Production of messenger RNA stops
48
Which of the following statements about the genetic code is/are correct?
A. A group of three nucleotides has only one meaning
B. An amino acid may be specified by one, two or more different triplets of nucleotides
C. The start signal is translated but the stop signals are not
D. All of
E. Two of
D. All of
49
The gene coding for the enzyme triose phosphate isomerizes in maize consists of over 3400 base pairs of DNA, but the corresponding messenger RNA is only 1050 nucleotides in length. What is the reason for discrepancy?
A. Only about one third of the gene is transcribed
B. The whole gene is transcribed, but about two thirds of the resulting RNA is discarded
C. The gene is only about one third of its normal length in the cells, which produce triose phosphate ismomerase.
D. Messenger RNA is very unstable, so that about two thirds of its length is lost during translation
B.The whole gene is transcribed, but about two thirds of the resulting RNA is discarded
50
A steroid hormone, like testosterone, works by
A. Combining with hormone receptor on cell surface, initiating a cascade of enzyme reactions inside cell leading to an effect of transcription
B. Crossing the cell membrane, leading to an effect on transcription by interacting with the mRNA
C. Combining with an intracellular hormone receptor, leading to an effect on transcription by interacting with mRNA.
D. Combining with an intracellular hormone receptor, leading to an effect on transcription by interacting with DNA
D. Combining with an intracellular hormone receptor, leading to an effect on transcription by interacting with DNA
51
Match the name of the enzyme to its functions or properties:
DNA ligase
A. This enzyme requires a DNA template
B. This enzyme catalyzes the breakage of DNA
C. This enzyme catalyzes the breakage of RNA
D. This enzyme catalyzes the removal of damaged DNA
E. This enzyme is not described by any of the above statements
E. This enzyme is not described by any of the above statements
52
Match the name of the enzyme to its functions or properties:
RNA polymerase
A. This enzyme requires a DNA template
B. This enzyme catalyzes the breakage of DNA
C. This enzyme catalyzes the breakage of RNA
D. This enzyme catalyzes the removal of damaged DNA
E. This enzyme is not described by any of the above statements
A. This enzyme requires a DNA template
53
Match the name of the enzyme to its functions or properties:
Restriction endonuclease
A. This enzyme requires a DNA template
B. This enzyme catalyzes the breakage of DNA
C. This enzyme catalyzes the breakage of RNA
D. This enzyme catalyzes the removal of damaged DNA
E. This enzyme is not described by any of the above statements
B. This enzyme catalyzes the breakage of DNA
54
Match the name of the information transfer process to its locations in a normal human cell:
Replication
A. Occurs in the nucleus
B. Occurs in the cytoplasm
C. Occurs in both the nucleus and the cytoplasm
A. Occurs in the nucleus
55
Match the name of the information transfer process to its locations in a normal human cell:
Transcription
A. Occurs in the nucleus
B. Occurs in the cytoplasm
C. Occurs in both the nucleus and the cytoplasm
A. Occurs in the nucleus
56
Match the name of the information transfer process to its locations in a normal human cell:
Translation
A. Occurs in the nucleus
B. Occurs in the cytoplasm
C. Occurs in both the nucleus and the cytoplasm
B. Occurs in the cytoplasm
57
Which of the following statements correctly describe a typical mammalian messenger RNA?
a. Messenger RNA has a cap at its 5end
b. Messenger RNA has a polyA tail at its 3end
c. Messenger RNA contains sections which as not translated
d. All of
e. Only two of
D. All of
58
An insulin-dependent diabetic has been injecting insulin regularly for ten years. His blood will most likely contain
a. Insulin, but no C peptide
b. Insulin and C peptide in approximately equal amounts
c. Insulin and a smaller amount of C peptide
d. Insulin and a larger amount of C peptide
A. Insulin, but no C peptide
59
Match the descriptions to the names of the sub cellular structures:
Ribosomes
A. This structure contains DNA
B. This structure participates in translation
C. Both A and B
D. Neither A nor B
B. This structure participates in translation
60
Which of the following is/are required for translation of messenger RNA?
a. Ribosomes
b. Amino acids
c. Transfer RNA
d. All of
e. Only two of
D. All of
61
In the ames test for carcinogenetic activities, the material to be tested is incubated with a liver extract before being brought into contact with test bacteria. This purpose of the liver extract is
a. To remove interfering substance from the material being tested
b. To sensitize bacteria to carcinogens
c. To convert non-reactive pre-carcinogens into more reactive substances
d. To convert DNA into a form that can react with carcinogens
e. To provide essential nutrients for bacteria
C. To convert non-reactive pre-carcinogens into more reactive substances
62
The function of the normal P53 gene (which is frequently mutated in cancer cells) is/are
a. To stop the progression of cells with damaged DNA around the cell cycle
b. To initiate apoptosis (programmed cell death)
c. To prevent the conversion of proto-oncogenes into oncogenes
d. All of
e. Only two of
E. Only two of
63
3. A single adenine (A) in the DNA of a fertilized human ovum was replaced by a cytosine (C). What is the likeliest result of this change?
a. No observable effect
b. Failure of the fetus to develop from the fertilized ovum, resulting in spontaneous abortion
c. Cancer in some tissue of the individual who develops from that fertilized ovum
d. An inheritable genetic disease in the individual who develops from that fertilized ovum
e. An inheritable genetic disease in the children or grandchildren of the individual who develops from fertilized ovum.
A. No observable effect
64
Cancer increases in frequency, as people get older. The main reason for this is
a. Older people are exposed to more cancer-causing substance in their diets
b. It takes many years to accumulate, by chance, the number of somatic mutations leading to disease
c. Cancer in young people are cured spontaneously, but in older people they are not
d. Somatic mutation occur more frequently as people get older
e. Proto-oncogenes become less stable as people age
B. It takes many years to accumulate, by chance, the number of somatic mutations leading to disease
65
Current strategies for treating disseminated cancers include the use of drugs that inhibit DNA replication. Normally tissues that are also affected by these drugs include
a. Skin
b. Skeletal muscle
c. Brain
d. All of
e. Two of
A. Skin
66
Benzo(a) pyrene in tobacco smoke, although a known carcinogen, is not mutagenic for bacteria unless it is first incubated with a liver extract. The reason is
a. Benzo(a) pyrene cannot react with DNA unless it is concerted into a more reactive compound
b. Benzo(a) pyrene can react with mammalian DNA, but not with bacterial DNA
c. Bacteria can inactive benzo(a)pyrene, but mammalian cells cannot
d. The DNA of mammalian cells is contained in the nucleus, but bacterial RNA is free in the cytoplasm
e. Benzo (a) pyrene can dissolve in mammalian cells, but not in bacteria.
A. Benzo (a) pyrene cannot react with DNA unless it is converted into a more reactive compound
67
Identify the kinds of immediate damage caused by the mutagenic agent:
Ultraviolet rays
A. Deamination of cytosine in DNA
B. Splitting of the linkages between sugars and bases in DNA
C. Joining of two adjacent thymines in DNA
D. Incorporation of wrong bases into DNA during replication
E. None of the above
C. Joining of two adjacent thymines in DNA
68
Identify the kinds of immediate damage caused by the mutagenic agent:
Nitrite
A. Deamination of cytosine in DNA
B. Splitting of the linkages between sugars and bases in DNA
C. Joining of two adjacent thymines in DNA
D. Incorporation of wrong bases into DNA during replication
E. None of the above
A. Deamination of cytosine in DNA
69
The P53 gene is a turmor suppressor gene. Cells in which this gene is disabled by mutation
a. Are unable to initiate apoptosis when their DNA is damaged
b. Proceed to replicate their DNA even when it is damaged
c. Both A and B
d. Neither A nor B
C. Both A and B
70
A proposed food additive that has been shown to be non-mutagenic for bacteria in the ames test is likely to
a. Be discarded, since it is probably carcinogenic
b. Be approved for use since it is probably not carcinogenic
c. Undergo further testing to ensure that it is not carcinogenic
C. Undergo further testing to ensure that it is not carcinogenic
71
In the following questions, match the descriptions to the kind of infectious agent:
Herpes virus
A. Contains all of DNA, RNA and enzyme protein
B. Contain either DNA or RNA, and enzyme protein
C. Contain both DNA and RNA, but no enzyme protein
D. Contain either DNA or RNA, but no enzyme protein
E. Contain proteins, but neither DNA nor RNA
D. Contain either DNA or RNA, but no enzyme protein
72
In the following questions, match the descriptions to the kind of infectious agent:
Bacteria
A. Contains all of DNA, RNA and enzyme protein
B. Contain either DNA or RNA, and enzyme protein
C. Contain both DNA and RNA, but no enzyme protein
D. Contain either DNA or RNA, but no enzyme protein
E. Contain proteins, but neither DNA nor RNA
A. Contains all of DNA, RNA and enzyme protein
73
In the following questions, match the descriptions to the kind of infectious agent:
Prion
A. Contains all of DNA, RNA and enzyme protein
B. Contain either DNA or RNA, and enzyme protein
C. Contain both DNA and RNA, but no enzyme protein
D. Contain either DNA or RNA, but no enzyme protein
E. Contain proteins, but neither DNA nor RNA
E. Contain proteins, but neither DNA nor RNA
74
In the following questions, match the descriptions to the kind of infectious agent:
Retrovirus
A. Contains all of DNA, RNA and enzyme protein
B. Contain either DNA or RNA, and enzyme protein
C. Contain both DNA and RNA, but no enzyme protein
D. Contain either DNA or RNA, but no enzyme protein
E. Contain proteins, but neither DNA nor RNA
D. Contain either DNA or RNA, but no enzyme protein
75
Which of the following statements about restriction endonuclease is correct
a. Restriction endonuclease catalyze the splitting of DNA but not of RNA
b. Restriction of endonuclease are found in bacteria, but not in mammalian cells
c. Restriction endonucleases can be used to attach radioactive or fluorescent labels onto DNA
d. All of
e. Only two of
E. Only two of
76
Patients with phenylketonuria (PKU) lack the enzyme that catalyzes the conversion of phenylalanine into tyrosine. As a result
a. Tyrosine is a nutritionally essential amino acid for these patients
b. Phenyl nine must be controlled in the diet of these patients
c. Both A and B
d. Neither A nor B
c. Both A and B
77
Which of the following processes goes on in cells infected with polio virus (an RNA virus) but not in normal cells?
a. RNA replication
b. Reverse transcription
c. Reverse translation
d. All of
e. Only two of
A. RNA replication
78
What distinguishes a genomic library from a cDNA library?
a. Genomic libraries from different tissues are all identical, but cDNA libraries differ from tissue to tissue
b. Genomic libraries contain introns, but cDNA libraries do not
c. Both A and B
d. Neither A nor B
C. Both A and B
79
The human genome project
a. On completion of the sequencing of the human genome, resulted in an international agreement to release all the data for study
b. Was funded exclusively by national institutes of health and the department of energy
c. Was limited to the study of humans
d. None of
e. Only two of
D. None of
80
During a virus infection, many progeny virus particles are produced, starting with a few infecting particles. The proteins of the progeny virus particles are made by using
a. The cellular ribosomes
b. The cellular transfer RNA’s
c. The cellular messenger RNA’s
d. All of
e. Two of
E. Two of
81
Which of the following statements correctly describe sucrose?
a. Sucrose cannot be absorbed from the intestine unless it is first digested
b. Consuming a diet high in sucrose leads to increased tooth decay
c. When a normal person eats sucrose, the concentration of glucose in the blood rises
d. All of
e. Only two of
D. All of
82
Match the descriptions to the names of the substance: bile salt
a. A substance resulting from the breakdown of fats
b. A substance resulting from the breakdown of heme
c. A substance derived from cholesterol
d. A consistent of lipoproteins
e. A constituent of cell membranes
C. A substance derived from cholesterol
83
Match the name of the enzyme to its description: lipoprotein lipase
a. This enzyme plays a part in the digestion of fats in the small intestine
b. This enzyme is activated during periods of starvation
c. This enzyme is located on the surface of cells lining the capillaries
d. This enzyme plats a part in the biosynthesis of fats
e. This enzyme is not described by any of the above statements
C. This enzyme is located on the surface of cells lining the capillaries
84
Match the description to the name of the plasma lipoprotein: chylomicron
a. This lipoprotein serves to transport cholesterol from peripheral tissues back to the liver
b. This lipoprotein is abundant in the blood of a person who has just had a meal, but almost absent just before the meal
c. Excessive amounts of this lipoprotein in the blood increase the risk of heart attack or stroke
d. This lipoprotein serves to transport triacylglycerol’s from the liver to peripheral tissues
e. This lipoprotein is not described by any of the above statements
b. This lipoprotein is abundant in the blood of a person who has just had a meal, but almost absent just before the meal
85
Compare the two hereditary abnormalities, lactose intolerance and galactosemia:
a. Lactose intolerance is comer than galactosemia
b. Lactose intolerance is less serious than galactosemia
c. With a suitable diet, people with lactose intolerance can lead a normal life, but people with galactosemmia seldom can
d. All of
e. Only two of
D. All of
86
When glucose is metabolized anaerobically by glycolysis, the product(s) is/are
a. Pyruvate and CO2
b. Lactate and CO2
c. Only pyruvate
d. Only lactate
e. Co2 and H2O
D. Only lactate
87
When an oral glucose tolerance test is given to a normal person, the concentration of glucose in the blood within the first 30 minutes
a. Increases from about 5 mM to about 7 mM
b. Does not change significantly
c. Decreases from about 7mM to about 5 mM
a. Increases from about 5 mM to about 7 mM
88
Match the descriptions to the names of the substance listed:
Starch
A. This substance consists entirely of glucose units
B. This substance is produced by plants, not by animals
C. Both A and B
D. Neither A nor B
C. Both A and B
89
Match the descriptions to the names of the substance listed:
Glycogen
A. This substance consists entirely of glucose units
B. This substance is produced by plants, not by animals
C. Both A and B
D. Neither A nor B
A. This substance consists entirely of glucose units
90
Which of the following substances can be absorbed from the intestine without digestion
a. Glucose
b. Lactose
c. Sucrose
d. Starch
e. Cellulose
A. Glucose
91
When mitochondrial oxidative phosphorylation is uncoupled
a. Heat production is increased
b. The rate of oxidation of substrate is increased
c. The rate of oxygen consumption is increased
d. All of
e. Only two of
D. All of
92
Which of the following statements about ketone bodies is/are correct?
a. Ketone bodies accumulate when a person eats a high carbohydrate diet
b. Accumulation of ketone bodies results in acidosis
c. Ketone bodies are the eventual products of the reaction catalyzed by hormone-sensitive lipase
d. All of
e. Only two of
b. Accumulation of ketone bodies results in acidosis
93
Match the name of enzyme to its description: hormone-sensitive lipase
a. This enzyme plays a part in the digestion of fats in the small intestine
b. This enzyme is activated during periods of starvation
c. This enzyme is located on the surface of cells lining the capillaries
d. This enzyme plats a part in the biosynthesis of fats
e. This enzyme is not described by any of the above statements
b. This enzyme is activated during periods of starvation
94
Which of the following is/are functions of the citric acid cycle?
a. Production of NADH and FADH2
b. Supplying the carbon skeletons for the synthesis of non-essential amino acids
c. Providing a starting point for gluconeogenesis
d. All of the above
e. Only two of
d. All of the above
95
Oxidative phosphorylation
= this process occurs in the mitochondria
96
Glycolysis
= this process occurs in the cytoplasm
97
In a tissue in which oxidative phosphorylation is uncoupled
a. ATP synthesis is decreased
b. Oxygen consumption is decreased
c. The number of mitochondria is decreased
d. All of
e. Only two of
a. ATP synthesis is decreased
98
The operation of the citric acid cycle can result in the oxidation of
a. Carbohydrates
b. Proteins
c. Fats
d. All of
e. Only two of
D. All of
99
When normally functioning mitochondria are supplied with oxidizable substrates and oxygen
a. The outside of the inner membrane is electrically positive with respect to the inside
b. The pH of the interior is lower than the pH of the inter-membrane space
c. Both A and B
d. Neither A nor B
a. The outside of the inner membrane is electrically positive with respect to the inside RIGHT ANSWER !!!
100
Compare the amount of ATP available from the complete oxidation of one molecule of glucose with that from the complete oxidation of one molecule of a fatty acid
a. Glucose gives more ATP than fatty acid
b. Fatty acid gives more ATP than glucose
c. Glucose and fatty acid give about the same amount of ATP
b. Fatty acid gives more ATP than glucose
101
Release of glucose into the blood from stored glycogen occurs
a. In liver but not in muscle
b. In muscle but not in liver
c. About equally in liver and muscle
d. In neither liver nor muscle
a. In liver but not in muscle
102
What is the effect of phosphorylation on the activity of glycogen phosphorylate
a. This enzyme becomes more active when it is phosphorylated
b. This enzyme becomes less active when it is phosphorylated
c. The activity of this enzyme is not affected by phosphorylation
a. This enzyme becomes more active when it is phosphorylated
103
What is the effect of phosphorylation on the activity of hormone sensitive lipase?
a. This enzyme becomes more active
b. This enzyme becomes less active
c. The activity is not affected
a. This enzyme becomes more active when it is phosphorylated
104
What is the effect of phosphorylation on the activity of acetyl-CoA carboxylase?
a. This enzyme becomes more active
b. This enzyme becomes less active
c. The activity of this enzyme is not affected
b. This enzyme becomes less active
105
Which of the following substance can serves as starting points for gluconeogenesis?
a. Lactate
b. Oxaloacetate
c. Acetyl CoA
d. All of
e. Only two of
E. Only two of
106
Match the names of the enzyme to its description: glycogen phosphorylase
a. This enzyme is present in liver but not in muscle
b. This enzyme is present in muscle but not in liver
c. This enzyme is present in both liver and muscle
d. This enzyme is present in neither liver nor muscle
c. This enzyme is present in both liver and muscle
107
Match the names of the enzyme to its description: glucose 6-phosphate
a. This enzyme is present in liver but not in muscle
b. This enzyme is present in muscle but not in liver
c. This enzyme is present in bother liver and muscle
d. This enzyme is present in neither liver nor muscle
a. This enzyme is present in liver but not in muscle
108
8. In a brief, intensive burst of exercise, the main source of ATP in the muscles is
a. Oxidative phosphorylation
b. Gluconeogenesis
c. Glycolysis
d. Fatty acid oxidation
e. Citric acid cycle
C. Glycolysis
109
9. Where in the cell are the B-oxidation enzymes located?
a. Mitochondria
b. Nucleus
c. Cytoplasm
d. Citric acid cycle
a. Mitochondria
110
10. Where in the cell are the fatty acid biosynthetic enzymes located?
a. Mitochondria
b. Nucleus
c. Cytoplasm
d. Golgi
C. Cytoplasm
