Tophat Questions Flashcards
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
D. Only two of A, B and C are correct
-A is wrong
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. Vitamins are essential nutrients
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
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.
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. Can result when the diet is deficient in protein
-More nitrogen excreted than ingested
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
D. 300 g
100 kg x 90=9000
9000/30 days=300
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%
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
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
B. 4, 9, 4
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
B. Thiamine
Solutions to be infused for total parental nutrition (TPN) contain A. Proteins B. Glucose C. Fats D. All of E. Only two of
E. Only two of
-Not glucose
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. TPN solutions contain amino acids, naso-gastric solutions contain proteins
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. All amino acids have a similar structure
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
B. Its biological activity is lost
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
C. Hydrogen bonds
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
E. None of the above
-Disulphide bridges are not easily broken. The treatments that break peptide linkages leave disulphide bridges intact
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
C. Loss of biological function (ex: catalysis)
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
C. The iron of hemoglobin remains in the Fe2 state in the course of its normally functioning
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
B. The shape of the oxygen dissociation curve of hemoglobin is sigmoid
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
D. All of the above
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. Improved oxygen delivery to tissues
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
C. In a diabetic patient with poor control of blood glucose
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
D. Neither A nor B
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. Enzymes
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. Enzymes can make reactions go faster than they would without enzymes
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
E. None of the above statements is correct
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
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
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
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
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
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
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
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
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
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
Dietary lack of vitamin C (ascorbic acid) results in impaired synthesis of
a. Collagen
b. Elastin
c. Keratin
d. Dna
e. RNA
A. Collagen
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
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
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
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
- 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
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
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
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
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