Practice exam - Chemistry
14 important questions on Practice exam - Chemistry
What method is depicted in the following figure?
- Non-competitive ELISA test
- Predictor test
- Direct competitive ELISA test
- Indirect competitive ELISA test
- Non-competitive ELISA test
- Predictor test
- Direct competitive ELISA test
- Indirect competitive ELISA test
What method is depicted in the following figure?
- Non-competitive ELISA test
- Predictor test
- Direct competitive ELISA test
- Indirect competitive ELISA test
- Non-competitive ELISA test
- Predictor test
- Direct competitive ELISA test
- Indirect competitive ELISA test
In the Codex Alimentarius “gluten-free” food is defined as food having less than:
- 200 ppm gluten
- 200 ppm gliadin
- 20 ppm gluten
- 20 ppm gliadin
- 200 ppm gluten
- 200 ppm gliadin
- 20 ppm gluten
- 20 ppm gliadin
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The basis of cross reactivity is:
- Family relation of plants (e.g. Wheat and rye or barley).
- The presence of the same stable structures in proteins (e.g. Alpha helix or barrel structures) providing stability and protection of the allergenic epitope.
- Sharing of similar sequences between proteins of different origin.
- Similar function of allergenic proteins (i.e. Related to the plant defence system).
- Family relation of plants (e.g. Wheat and rye or barley).
- The presence of the same stable structures in proteins (e.g. Alpha helix or barrel structures) providing stability and protection of the allergenic epitope.
- Sharing of similar sequences between proteins of different origin.
- Similar function of allergenic proteins (i.e. Related to the plant defence system).
A company wants to produce a hydrolyzed cereal protein product that is also suitable for celiac disease patients. The company has to select a suitable mix of cereal proteins to start with. Rank the products in order from high to low suitability:
- Wheat > Barley > Oats > Corn
- Oats > Barley > Corn > Wheat
- Corn > Barley > Oats > Wheat
- Corn > Oats > Barley > Wheat
- Wheat > Barley > Oats > Corn
- Oats > Barley > Corn > Wheat
- Corn > Barley > Oats > Wheat
- Corn > Oats > Barley > Wheat
When threshold levels for allergic reactions (LOAELS) are measured in a DBPCFC, there may be quite considerable variation in the outcomes. What is(are) the cause(s) for this?
- 1. The characteristics of patients differ across Europe
- 2. The composition of the matrix in which an allergen is masked, is important for the outcome
- 3. The outcome depends on the type of statistical analysis
- 1 and 2, but not 3, are true
- 1. The characteristics of patients differ across Europe
- 2. The composition of the matrix in which an allergen is masked, is important for the outcome
- 3. The outcome depends on the type of statistical analysis
- 1 and 2, but not 3, are true
What protein family does NOT belong in the major allergen families from animals?
- Cupins
- Caseins
- Parvalbumins
- Tropomyosins
- Cupins
- Caseins
- Parvalbumins
- Tropomyosins
Dot-blotting, ELISA and Western Blotting can be used for the detection of allergen. Which additional information is provided with Western Blot compared to the other two detection method?
- The concentration of the antigen
- The conformation of the antigen
- The size of the allergen
- The amino acid sequence
- The concentration of the antigen
- The conformation of the antigen
- The size of the allergen
- The amino acid sequence
Which statement on protein structure is true?
- The primary protein structure is amino acids linked together by ester bonds
- The secondary protein structure is stabilised only by non-covalent bonds.
- The tertiary protein structure stabilises the protein and involves the formation of beta-sheets.
- All proteins have a quaternary structure.
- The primary protein structure is amino acids linked together by ester bonds
- The secondary protein structure is stabilised only by non-covalent bonds.
- The tertiary protein structure stabilises the protein and involves the formation of beta-sheets.
- All proteins have a quaternary structure.
What is the expected adverse reaction in humans that may occur related to these compounds: 1/ Caffeine and 2/ Lead?
- 1 - Pharmacological reactions, 2 - Toxic reactions
- 1 - Pharmacological reactions, 2 - Pharmacological reactions
- 1 - Toxic reactions, 2 - Toxic reactions
- 1 - Toxic reactions, 2 - Pharmacological reactions
- 1 - Pharmacological reactions, 2 - Toxic reactions
- 1 - Pharmacological reactions, 2 - Pharmacological reactions
- 1 - Toxic reactions, 2 - Toxic reactions
- 1 - Toxic reactions, 2 - Pharmacological reactions
Below you will find a so-called motif for an allergenic protein:
.....-XXXXQPPQQPVPTYQPTTXXXX-.....
Q=Glutamine; P = Proline; Y = Tyrosine; V = Valine; T = Threonine;
Underlined = Essential; X = Non-essential; Non-underlined = unknown (could be essential or not).
Based on its motif, this allergenic epitope is most likely:
- A linear epitope and therefore thermostable.
- A linear epitope and therefore not thermostable.
- A conformational epitope and therefore thermostable.
- A conformational epitope and therefore not thermostable.
- A linear epitope and therefore thermostable.
- A linear epitope and therefore not thermostable.
- A conformational epitope and therefore thermostable.
- A conformational epitope and therefore not thermostable.
A dose-response curve was constructed from the allergenic reactions of individuals against hazelnuts. Which of the following statement is true?
- A is the NOAEL
- A is the IC10
- B is the NOAEL
- B is the LOD
- A is the NOAEL
- A is the IC10
- B is the NOAEL
- B is the LOD
During heat treatment, several changes occur. Which of the following statement is NOT true?
- Heat-treatment does not change linear epitopes.
- Heat-treatment does not change conformational epitopes.
- Heat treatment results in a decrease in allergenicity.
- Heat treatment results in an increase in allergenicity.
- Heat-treatment does not change linear epitopes.
- Heat-treatment does not change conformational epitopes.
- Heat treatment results in a decrease in allergenicity.
- Heat treatment results in an increase in allergenicity.
Cross contaminating allergens are:
- Formed during processing.
- Typically due to inadequate cleaning of production lines.
- Hidden inside a protein due to its conformation.
- Related to interaction of proteins with other food ingredients.
- Formed during processing.
- Typically due to inadequate cleaning of production lines.
- Hidden inside a protein due to its conformation.
- Related to interaction of proteins with other food ingredients.
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