Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

TOX > Chemical tox > Flashcards

Chemical tox Flashcards

1
Q 
Which of the following would you consider not to be a xenobiotic compound to humans? 
Penicillin 
lysergic acid 
ochratoxin A 
lactic acid
A

lactic acid (body makes it naturally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Define toxicity

A

acute death, cancer, teratogenicity, allergic reactions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

to say that a substance is non -toxic means that:

A

it would require a large dose to cause toxic effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q 
Comparing the toxicity of a toxicants in rats vs humans could be considered to be an example of: 
comparative toxicology
epidemiology
Bradford-hill criteria 
inter-species extrapolation 
toxicity towards a non-target organism
A

toxicity towards a non-target organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

According to IRAC, ochratoxin A is classified as what type of carcinogen?

A

Group 2B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which compounds give a J-shaped hormetic dose-response relationship

A

Ethanol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which dose-response relationship is used to characterize carcinogens?

A

linear dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

According to Environment Canada a compound with a logKow greater then ? is likely to bioaccumulate

A

3.7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q 
Which compound has the lowest logKOW value 
pyrene
naphthalene 
dichlorobenzene 
phenol 
benzene
A

phenol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q 
Which compound has the highest logKOW value 
benzene 
hexachlorobenezene 
pyrene 
benzo[a]pyrene
phenanthrene
A

benzo[a]pyrene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q 
which compound I snot a surfactant 
sodium dodecylsulfate 
soap
prostanoic acid 
bile salts
octanol
A

octanol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What type of surfactant aggregate is produced in non polar solvents

A

reverse micelles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

for a substance wit chemical structure phCH2CH2CO2H, th epic is likely to be close to

A

5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

for cocane, a base whose pka is 8.6, water solubility is likely to be highest at pH

A

3.5 so its protonates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

cocane, whose pjs is 8.6 is likely to be absorbed from the GI tract in the

A

small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

pjs of anthracine is likely to be close to

A

none of the above

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

anthracine is likely to be absorbed from the GI tract in the

A

(anywhere)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q 
from the list below choose the stringiest nucleophile in water 
OH
NH3
F-
HS-
phenoxide
A

hs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q 
From the list below choose the stringiest nucleophile in DMSO
water 
phenol 
HS
OH
A

oh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

which solvent I snot classified as polar protic

A

DMF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does metabolism allow

A

the enzymatic conversion of chemicals to more polar compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

primary site of xenobiotic metabolism

A

liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

CYP450 derives its name from optical properties of

A

Fe(II)-Cyp450-CO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

define polar protic

A

polar protic solvent are capable of hydrogen bonding because they contain at least one hydrogen atom attached to one electronegative atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what makes a polar functional group

A

if its hydrophilic (water loving), its polar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

examples of polar fictional groups

A

OH, NH2, Co2H

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

where are polar substances NOT taken up

A

the gut (does not break the barrier)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what makes a functional group non-polar

A

hydrophobic/lipophilic substance (most likely a hydrocarbon functional group)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What three atoms can be added to molecules to make them more lipophilic

A

BR, CL, I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What effect does Cl, BR, and I have on a molecule

A
  • increases lipophilicity

- increases London forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

describe solubility with polar/nonpolar

A

like dissolves like (polar W polar, Nonpolar W non polar)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is the equation for partition constant

A

k= ([ solute in solvent 2])/([] soute in souvent 1])

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are the consequences of having his lipophilictty

A

1) uptake into fatty tissues

2) bioaccumulation (>3.7)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

equation for relationship between KOW and bioconcentration factor

A

Bcf= [toxicant in aquatic organism]/[toxicant in surrounding water]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

name 6 aromatic compounds

A

benzen, naphalene, anythracenbe, phenaline, pyrene, benzo[a]pyrene],[benzo[2]pyrene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what is an aromatic compound

A

contain conjugated planar ring systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

what does surfactant stand for

A

surface active agent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

describe the formation os micelles in polar solvent

A

anything with the hydrophobic tails pointed in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

describe the formation of micelles in non polar solvent

A

anything with hydrophobic tails pointed out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what is a prostaglandin

A

a family of compounds that have the 20-carbon skeleton of prostanoic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

how are prostaglandins made in the body

A

synthesized from membrane-bound 20-carbon polyunsaturated fatty acids in response to specific body triggers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

name a biological surfactant

A

bile salt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

what do bile salts fo

A

act as a surfactant

emulsify lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

describe heterolytic bond cleavage

A

only one of the atoms gets the electrons, the other one gets nothing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

describe hemolytic bond cleavage

A

both of the atoms get an electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

name the three hydrogen halides

A

Hal
Hbr
HI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

name the tree oxides

A

H2SO4
HNO3
HCLO4

48
Q

main acid/base property of xenobiotics

A

the uncharged form of the acid or base is more lipophilic (and more easily taken up in the GI tract)

49
Q

describe acid/base properties of carboxylic acids and phenols

A

acidic conjugate is uncharged, basic conjugate is ionic

50
Q

describe acid/base properties of nitrogen bases

A

acidic conjugate is ionic, basic conjugate is uncharged

51
Q

what is a nucleophile

A

an electron-rich molecule that has at least one pair of unshared electrons

52
Q

what charge do nucleophiles usually have

A

negative

53
Q

what are the four factors that contribute to nucleophilicity

A

charge
electronegativity
solvet
steric hindrance

54
Q

describe how charge effects nucleophilicity

A
  • the conjugate base of a neutral species is always a better nucleophile
  • nucleophilicity increases with electron density
55
Q

describe how electronegativity effects nucleophilicity

A

nucleophilicity increases with decreased electronegativity

th less electronegative an atom, the less tightly-held the electrons will be

56
Q

describe how the solvent effects nucleophilicity

A

nucleophilicity increases going down the periodic table

57
Q

describe how steric hindrance effects nucleophilicity

A

bulkiness/shape/greasiness

58
Q

Describe the bonding between polar solvent and nucleophiles

A

a polar solvent can participate in hydrogen bonding with a nucleophile, creating a shell of solvent molecules. This makes the nucleophiles less reactive

59
Q

why does bonding between polar solves and nucleophiles make the nucleophiles less reactive

A

the lone pairs of electrons are interacting with the electron-poor hydrogen atoms of the solvent

60
Q

describe nucleophilicity within polar parotid solvents

A

in polar parotid solvents, nucleophilicity increases going up the periodic table

61
Q

what are the six types of reaction intermediates

A
  • carbon or nitrogen atoms attached to a leaving group
  • carbocations
  • carbonyl compounds
  • alphs-beta-unsaturated carbonyl compounds
  • quinones
  • epoxides
62
Q

define the relative stability of carbocations

A

3>2>1>methyl

63
Q

what is found in carbonyl compounds

A

electrophilic carbons

64
Q

what are quinones

A

cyclic conjugated dikeytones

65
Q

what are epoxides

A

statically hindered ethers

66
Q

describe epoxide reactions

A

all involve nucleophilic attach at the carbon atoms (which leads to opening of the ring)

67
Q

what is the driving force of epoxide reactions

A

the driving force is the relief of steric strain

68
Q

describe a radical

A

always have at least one unpaired electron and usually very reactive

69
Q

what radical reaction is least likely to happen

A

termination

70
Q

define oxidative stress

A

an excess of prooxidant over antioxidant reactive species

71
Q

what is the result of oxidative stress

A

-damage to proteins, lipids,nucleic acids

72
Q

why is oxidative stress caused

A

its the result of exposure to reactive oxygen species

73
Q

explain metabolism

A

allows the enzymatic conversion of compounds too more polar compounds

74
Q

after metabolism, why are the compounds changed to more polar versions of themselves

A

to be more easily excreted

75
Q

compare metabolites to the parent compounds

A
  • most metabolites are more water-soluble than the parent compound
  • most metabolites tend to be more ionized than the parent compound
  • metabolited tend to less active
76
Q

what is a pro drug

A

therapeutic agents that must be first metabolized to be activated

77
Q

what are proximal carcinogens

A

chemical carcinogens where the parent compound itself is not carcinogenic

78
Q

where is the primary site of xenobiotic metabolism

A

the liver

79
Q

explain the first pass effect

A

when most agents pass through the liver prior to reaching their target site. Results in a portion to be inactivated/activated in the wrong place (liver)

80
Q

what types of reactions are involved in phase 1 metabolism

A

hydrolysis, oxidations, reduction

81
Q

describe the increase in polarity within phase 1 metabolism

A

the increase in polarity is small

82
Q

what is the general mechanism of phase 1 metabolism

A

the exposure of functional groups

83
Q

describe the consequences of phase 1 metabolism

A

results in metabolic activation

84
Q

what types of reactions are involved within phase 2 metabolism

A

conjugation

85
Q

describe the change in polarity with phase 2 metabolism

A

large increase in polarity

86
Q

describe the general mechanism of phase 2 metabolism

A

polar compounds are added to functional groups

87
Q

what is the consequence of phase 2 metabolism

A

facilitates excretion

88
Q

what is cytochrome p450 responsible for

A

responsible for the majority of the biotransformation reactions used to metabolize endogenous and exogenous compounds

89
Q

what is cytochrome p450

A

microsomal enzymes: membrane-bound vesicles that result from the fragmentation of the endoplasmic reticulum

90
Q

what is the mechanism of cytochrome p450

A

they catalyst the insertion of one molecule of oxygen into the substrate (one O atom is inserted into the chemical and the other is reduced to form H2O

91
Q

The unusual 450m, absorption is de to

A

fe(2) binding to cysteine-thiolate

92
Q

what is the MAJOR reaction type in phase 1 metabolism

A

oxidation

93
Q

what is the MAJOR reaction type in phase 2 metabolism

A

conjugation

94
Q

which phase 2 reaction increases metabolites stability compared to the parent compound

A

N-acetylation

95
Q

which phase 2 reason traps reactive intermediates?

A

glutathione conjugation

96
Q

which amino acids make up glutathione

A

glutamic acid, cysteine, glyceine

97
Q

in reverse-phase HPLC, the mobile phase typically consists of?

A

water-acetonitrile

98
Q

in reverse-phase hplc, what would be the expected order of elution in water (pH5)-acetonitrile (phenol, pyrene, toluene, benzoic acid)

A

benzoic acid, phenol, toluene, pyrene)

99
Q

to be detected in positive mass spectrometry, describe the weight the ions must be

A

must be heavier than the initial compound

100
Q

to be detected in negative mass spectrometry, describe the weight the ions must be

A

must be lighter than the initial compound

101
Q

for separation of OTA and its metabolites in reverse-phase HPLC, pH pf the middle phase should be:

A

1

102
Q

use of gluceronic acid

A

gluceronic acts is the mail sugar used to prevent the accumulation of waste products of metabolism

103
Q

what us an aglycone

A

a compound without a sugar

104
Q

what gets added to aglycone to form a gluceronide

A

UDPGA + aglycone= gluceronide + UDP

105
Q

what prevents hydrolysis by peptidases

A

peptide linkage

106
Q

what form of GHS is a good nucleophile

A

ionized thionate form of GHS is a good nucleophile

107
Q

what makes GSH a good reductant

A

ability of surfer to donate electrons

108
Q

what enables defence against oxidative stress

A

GSH

109
Q

difference in liquid chromatography and high performance liquid chromatography

A
  • high degree of separation

- one solvent composition

110
Q

describe a gradient system

A
  • varying eluent composition
  • varying solvent composition
  • can be either high or low pressure
111
Q

describe an isocratic system

A
  • constant fluent composition

- one solvent composition

112
Q

benefit to isocratic system

A

useful if you want one peak and don’t care about poor separation

113
Q

benefits to gradient system

A

good peak separation

114
Q

describe stationary phase in reverse phase chromatography

A

low polarity

made of octadecyl group-bonded silica gel (ODS)

115
Q

what is the stationary phase in reverse phase chromatography made of

A

ODS

116
Q

describe mobile phase in reverse phase chromatography

A

high polarity

usually water+acetonitrile

TOX (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions