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1
Q

Methylated flavonoids

A

are more _____.

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2
Q

Which analytical techniques were used to identify Brassica napus flavonoids induced by UVB?

A

Flavonoid extraction, High-performance liquid chromatography, Western blot analysis, Mass spectrometry.

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3
Q

Which enzymes in Brassica napus are upregulated by UVB?

A

Superoxide dismutase, Chalcone synthase, Phenylalanine ammonia-lyase, Peroxidase.

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4
Q

Flavonoids make up 10 classes and 20 skeletons.

A

False.

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5
Q

Tumours seem to accumulate photodynamic photosensitizers from the blood stream to a greater extent than healthy tissues.

A

True.

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6
Q

_____ are characterized by a link between the B ring and position 4 of the C ring.

A

Flavones.

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7
Q

Which of the following are characteristics of flavanones?

A

Sources include oranges, lemons, grapes; Antioxidant/anti-inflammatory/cholesterol-lowering; Examples: hesperitin, naringenin, eriodictyol; Found in leaves, flowers, and fruits.

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8
Q

Flavonoids help metal absorption (e.g., iron) because they chelate metals.

A

True.

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9
Q

Cyanic colour is stable and the basis of colour variety.

A

True.

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10
Q

Each different aggregate will have a different colour.

A

True.

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11
Q

Select the incorrect statement.

A

UVA is increasing due to ozone loss.

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12
Q

Functions of flavonoids in plants:

A

Freezing tolerance, Heat acclimatization, Drought resistance, Flood resistance.

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13
Q

CRISPR-Cas9 edits genomes by adding/removing/changing DNA.

A

True.

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14
Q

Common flavonoid modifications:

A

Dimerization/oligomerization, Conjugation to sugars, O-methylation/O-acylation, Metal chelation.

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15
Q

Hydroxyl radical (from H₂O₂) can attack any biomolecule.

A

True.

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16
Q

Loss of water in plant vacuoles is called _____

A

Vacuolysis.

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17
Q

Aggregates absorb as a single molecule.

A

True.

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18
Q

Isoflavonoid characteristics:

A

Examples include hesperitin, naringenin, eriodictyol; Found in leaves only; Sources include soybeans & legumes; Beneficial health effects include: Antioxidant/anti-inflammatory and cholesterol-lowering.

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19
Q

Select the incorrect statement.

A

Phenols derived from ferulic & coumaric acid.

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20
Q

Which of the following are characteristics of psoralen:

A

Psoralen inhibits cell division; Psoralen-DNA adducts are formed via the via Diels–Alder reaction; Psoralen is well-established for photodynamic therapy (PDT); If two adenines are in opposite strands of a DNA (or RNA) molecule, the strands can be covalently crosslinked via psoralen.

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21
Q

Flavonoids do not influence food production since they’re not involved in pollination.

A

False.

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22
Q

_____ is responsible for the distinctive bitter taste of beer.

A

Hops.

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23
Q

Select the incorrect statement.

A

UV (400–700 nm) causes electronic transitions.

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24
Q

To prevent skunky flavour in beer:

A

Store in dark, Use brown/green bottles, Remove the flavour after production, Stabilize the molecules.

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25
Select the incorrect statement.
Iso-α-acid flavour threshold is 10.6 ppm.
26
Select the correct equation for energy.
Energy = hc/λ.
27
Correct flavonoid biosynthesis order:
D, B, A, C.
28
Which of the following are characteristics of chalcones:
C ring is absent; Examples: phloridzin, arbutin, phloretin; Sources include tomatoes, pears, strawberries, bearberries, and wheat products; Found in leaves, flowers, fruits.
29
There is one main structural difference between kaempforal and quercetin.
Which one would you expect to be more water soluble?
30
Phenylalanine → 4-coumaroyl-CoA is the committal step.
False – formation of chalcone.
31
Anthocyanin colour depends on pH.
True.
32
Which of the following are functions of flavonoids in plants?
Flower pigments, Free radical scavengers, UV-absorbing compounds, Allelopathic defense.
33
Which molecule absorbs at a higher wavelength: Molecule A with 5 π bonds or Molecule B with 6 π bonds?
Molecule B (6 π bonds).
34
Fill in the blanks: _____ charge in the _____ ring can be attacked by OH⁻.
Positive; pyran.
35
Fill in the blank: Yellow flower colouring results from transmission at _____.
550 to 600 nm.
36
Final stage of flavonoid biosynthesis occurs in cytoplasm.
False.
37
Maillard reaction products come from sugar oxidation/modification.
True.
38
Fill in the blank: Flavonoids are transported via a _____.
Glycosyl group.
39
Which of the following are characteristics of flavanols:
Pigments for colour in plants/fruits; No double bond between positions 2 and 3; Have a hydroxyl group at position 2; Sources include celery, parsley, red peppers.
40
Which of the following are types of aggregates?
Self-association, Intramolecular copigmentation, Intermolecular copigmentation, Metal complexity.
41
Which of the following are characteristics of aggregates?
Aggregates stack in a planer fashion promoting π-π interactions and hydrophillic interactions; Aggregates increase association properties with sugars at 3 and 5 positions; Aggregates require a free 3' hydroxy for their formation; Aggregates protect the charge in the ring from OH⁻ attack.
42
Which of the following is the precursor to all flavonoids:
Chalcones.
43
Select the incorrect statement.
Benzophenone sequence fits Type I mechanism Benzophenone.
44
Which of the following are characteristics of Flavones?
Responsible for the bitter taste of the juice and peel of citrus fruits; Beneficial health effects include: antioxidant, anti-inflammatory, and cholesterol-lowering; Sources include celery, parsley, red peppers.
45
Select the incorrect statement.
Net electron spin in organics is 0.
46
Fill in the blank _____ is the source of the distinctive bitter taste of beer.
Hops.
47
Select the reason why butadiene absorbs at a longer wavelength than ethylene:
One more double bond.
48
Once energy is absorbed, it must be dissipated by the molecule.
Rank butadiene, ethylene, and hexatriene from highest to lowest dissipation.
49
Energy is directly proportional to λ.
False.
50
Fill in the blank: _____ are characterized by a link between the B ring and position 3 of the C ring.
Neoflavonoids.
51
Flavonoids are usually found in the cytoplasm of the plant cell.
False.
52
Select the incorrect statement.
Flavonoids are found only in the leaves of a plant.
53
Extracellular flavonoids can be found in waxy layers and cuticles.
True.
54
Select the correct equation for absorbance.
Absorbance = εcl.
55
Which of the following are correct statements?
Flavonoids are found in the mesophyll layer of leaves; Flavonoids are found in the epidermal layers of petals; Anthocyanins are copigments that reinforce flavonone pigmentation (i.e., produce red, purple, blue pigments); Flavonoids are found in the epidermal layers of leaves.
56
Which of the following are characteristics of anthocyanins?
Sources include cranberries, black currants, red grapes, raspberries, strawberries, blueberries, bilberries, and blackberries; Examples include cyanidin, delphinidin, malvidin, and peonidin; Beneficial health effects include: antioxidant, anti-inflammatory, and cholesterol-lowering; Pigments responsible for colours in plants, flowers, and fruits.
57
Fill in the blank: ___________ is responsible for colour formation in beer.
Hops.
58
Hops is the source of the skunky flavour in light-struck beer.
True.
59
For an organic molecule to absorb light, it must have conjugated double bonds (or a conjugated π-orbital system).
True.
60
Fill in the blanks: Yellow flower colouring results from a combination of anthocyanins (absorbance at _______) and carotenoids (absorbance at _______).
450 to 550 nm; 400 to 500 nm.
61
The composition of beer (from barley and hops) is … 81% water, 10 ethanol, 5% carbs/malt, etc.
True.
62
Fill in the blanks: The pH of the vacuole is _____, which ____ the charge.
acidic; protects.
63
Fill in the blank: The caramelization in many foods from heating results in _____.
Maillard reaction products.
64
Which of the following are characteristics of Neoflavonoids?
Have a hydroxyl group at position 2.
65
vacuole is _____, which ____ the charge.
a. acidic; destabilizes
66
Fill in the blank: The caramelization in many foods from heating results in _____.
d. Maillard reaction products
67
Which of the following are characteristics of Neoflavonoids? (Select all that apply)
a. Have a hydroxyl group at position 2 b. Found in the bark and timber of the common Sri Lankan tree, Mesua thwaitesii c. Used widely in the pharmaceutical industry d. Beneficial health effects include: antioxidant, anti-inflammatory, and cholesterol-lowering
68
Which of the following are compounds altered or made toxic by UV light? (Select all that apply)
a. Thymine dimer b. Tyrosine c. Tryptophan d. Threonine
69
Solutions of anthocyanin(s) deviate from Beer’s Law as anthocyanin concentration…
b. increases because absorbance saturates and no longer increases
70
Flavonoids are one of the largest and most important groups of allelochemicals.
a. True
71
Daffodils normally appear yellow. Dr. Igboeli decides to en.... What pigment would he have to produce to achieve this colour?
a. delphinidin
72
Which of the following are characteristics of Chalcones?
a. Open-chain form of flavonoids that lack the pyran ring b. Have a 1,3-diaryl-propane skeleton c. Have a 4-arylchromane skeleton d. Account for less than 1% of flavonoids
73
There is one main structural difference between kaempferol and quercetin? Also, which of these molecules is more water soluble?
a. Kaempferol has one more hydroxy at the 4' position and this makes it more water soluble
74
Which of the following are characteristics of Isoflavonoids?
a. Are phytoalexins - defense against both fungi and bacteria b. Have a C15 skeleton c. Have a 4-arylchromane skeleton d. Account for less than 1% of flavonoids
75
Excessive increase of intracellular ROS is tracked using markers (e.g., SOD, POD, CAT, GSH). An increase in those markers represents an increase in ROS.
b. False - markers are used to measure getting rid of ROS
76
Tumours seem to accumulate photodynamic photosensitizers from the blood stream to a greater extent than healthy tissues. A possible explanation for this is that tumours require energy and there are lots of double bonds in photosensitizers which provide energy when broken.
a. True
77
Dr. Igboeli had two different dishes stored in the same type...ed; however, the dish that was 4 weeks old was not. Why is that?
a. The 4-week old dish had alcohol in it - alchohol HOPS originally used a preservative
78
Which of the following are reasons why it is difficult to identify secondary metabolites? (Select all that apply.)
a. Long-lived b. Hard to separate c. Not volatile enough d. Too large concentrations
79
Which of the following are types of relationships that can be formed between organisms via influence of allelochemicals? (Select all that apply.)
a. Competition b. Hostility c. Cordiality d. Mutualism
80
Which of the following are functions of allelochemicals? (Select all that apply.)
a. Insecticides – insect repellent b. Phytoalexins (antimicrobial defense only) c. Phytoalexins (antifungal defense only) d. Herbicides – competition
81
Allelopathic chemicals are phytoalexins defense against both fungi and bacteria
82
Which of the following are functions of allelochemicals? (Select all that apply.)
a. Attract enemies of predators b. Seed dispersal - flavor: terpenoids, color: flavonoids/carotenoids c. Attract bees to flowers - flavonoids d. Insect repellant - capsaicin, hypericin
83
Which of the following are strategies evolved by insects to cope with plant toxins? (Select all that apply.)
a. Excretion b. Degradation c. Sequestration d. Avoidance
84
Day length regulates allelochemical production.
a. True
85
Fill in the blanks: ______ eat a wide variety of plants, whereas...rely on one food source, often to the exclusion of all other available foods.
b. Generalists; specialists
86
Select the word that best describes allelopathy.
c. Defense
87
Which of the following are physical features developed by plants to defend themselves against insects? (Select all that apply.)
a. Hardened leaves - sclerophyll b. Waxy cuticles c. Thorns d. Spines
88
Lignin consists of hundreds or thousands of phenolic monomers and is insoluble, rigid, and nearly indigestible.
a. True
89
Select the incorrect statement.
b. Lipid oxidation products are long chain aldehydes and long chain en-ols - short chain aldehydes and enols (low conc)
90
Daffodils normally appear yellow. The F3'5'H enzyme gene is cloned into daffodils and they now start to produce large amounts of delphinidin. What color are they now?
b. Purple
91
Leaves of Cestrum nocturnm, Cestrum diurnum, and Asclepias curassavica are rich sources of saponins that are used to kill mosquito larva
a. True
BIOL 439
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