Brainscape's Knowledge GenomeTM

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


See full index

Toxicology > Mechanisms of Toxicology 2 > Flashcards

Mechanisms of Toxicology 2 Flashcards

1
Q

three destinies a cell can take

A

division
differentiation
apoptosis

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

the nature of primary cellular dysfunction caused by toxicants depends on the role of the ____

A

target molecule

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

if the target molecule is involved in cellular regulation____

A

dysregulation of gene expression and/or dysregulation of momentary cellular function occur

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

if the target molecule is involved in the cell’s internal maintenance…

A

the dysfunction can compromise the survival of the cell

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

when two receptors receive a molecule such as a hormone

A

dimerization

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

what are two things that can happen for dysregulation of transcription

A

interaction with the transcription factor

change of response element

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

Receptor activation ultimately leads to

A
  1. altered gene expression that increases or decrease the quantity of a specific protein
  2. causes a chemical modification of a protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

can repress translation of mRNA into proteins, regulating protein synthesis posttranscriptionally

A

microRNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Transcription of genetic information from DNA to mRNA and miRNA is largely controlled by

A

interplay between TFs and regulatory promoter region of genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Xenobiotics may interact with TFs ….

A

altering the promoter region of the gene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

in addition to altering the fate of specific cells, compounds that act on ligand activated TFs can also evoke change in

A

the metabolism of endobiotics and xenobiotics by inducing overexpression of relevant enzymes

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

increased promotor methylation by a toxicant can

A

silence genes

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

decreased methylation by a toxicant can

A

activate more genes

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

protein protein interactions are called

A

dimerization

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

causes phosphorylation

A

protein kinase

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

causes dephosphorylation

A

protein phosphatase

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

proliferative effects in the dyregulation of signal transduction

A

activate protein kinase or deactivate phosphatase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

antiproliferative effects of dysregulation of signal transduction

A

inhibit kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

critical biochemical disorders that cause alteration of cellular maintenance

A

ATP depletion
calcium accumulation
ROS/RNA generation

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

xenobiotics that facilitate phosphorylation of signal transducers often promote

A

mitosis or tumor formation

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

chemicals may alter synaptic levels of neurotransmitters by

A

interfering with their synthesis, storage, release, or removal from the vicinity of the receptor

22
Q

plays a central role in cellular maintenance both as a chemical for biosynthesis and as the major source of energy

A

ATP

23
Q

when ADP is rephosphorylated in the mitochondria by ATP synthase. Coupled to oxidation of hydrogen to water

A

oxidative phosphorylation

24
Q

interfere with the delivery of hydrogen to the electron transport chain

A

class A

25
Q

inhibit the transfer of electrons along the electron transport chain to oxygen

A

class B

26
Q

interfere with oxygen delivery to terminal electron transporter, cytochrome oxidase

A

class C

27
Q

inhibit the activity of ATP synthase

A

class D

28
Q

synthesis of ATP may be inhibited in one of four ways

A
  1. direct inhibition of ATP synthase
  2. interference with ADP delivery
  3. interference with inorganic phosphate delivery
  4. deprivation of ATP synthase from its driving force, the controlled influx of protons
29
Q

chemicals causing mitochondrial DNA injury and there by impairing synthesis specific proteins encoded by the mitochondrial genome

A

class E

30
Q

examples of class A chemicals

A

fluoroacetate

arsenite

31
Q

examples of class B chemicals

A

Rotenone

cyanide

32
Q

examples of class C chemicals

A

CO

alkaloids

33
Q

Example of class D chemical

A

DDT

34
Q

example of class E chemicals

A

antiviral (AIDS) drugs

35
Q

sustained elevation of intracellular calcium is harmful because it can result in

A
  1. depletion of energy reserves
  2. dysfunction of microfilaments
  3. activation of hydrolytic enzymes
  4. generation of ROS and RNS
36
Q

what happens during mitochondrial permeability transition

A 
abrupt membrane leak
proton influx and loss of electrical gradient 
ATP synthesis stops
swelling from influx of water
Calcium efflux
sudden cell death or necrosis
37
Q

programmed cell death

A

apoptosis

38
Q

four steps of apoptosis

A
  1. release of cytochrome c
  2. activation of caspases
  3. formation of membrane bound fragments
  4. phagocytosis by macrophages
39
Q

apoptosis requires

A

ATP

40
Q

cysteine proteases that cleave proteins after specific asparate residues. they reside mostly in the cytoplasm in inactive forms with are activated by dimerization or proteolytic cleavage

A

caspases

41
Q

what decides whether a cell goes through apoptosis or necrosis

A

the severity of MPT

42
Q

if there is low MPT

A

lysosomal autophagy of leaking mitochondria

43
Q

if there is intermediate MPT

A

caspase activation and apoptosis

44
Q

if there is high MPT

A

cytolysis and necrosis

45
Q

four other mechanisms that lead to cell death

A

membrane damage by solvents, detergents, venom enzymes
lysosomal damage
disintegration of cytoskeleton
disruption of protein synthesis

46
Q

three ways proteins are repaired

A

ezymtically to may thiol groups into disulfides
with heat shock proteins or chaperones
breakdown of protein using ubiquitin

47
Q

how are lipids repaired

A

repair of fatty acid tails by phospholipases

48
Q

how is DNA repaired

A

multiple systems

49
Q

is cellular repair ever done

A

rarely, most cells are replaced

exception is neuronal cells

50
Q

three steps in repair of tissues with germ cells

A

induction of mitosis
dedifferentiation, followed by redifferentiation
production of extracellular matrix

51
Q

Three things that can happen when tissue repair fails

A

tissue necrosis
fibrosis
carcinogenesis

52
Q

four mechanisms of adaptation

A

decreasing delivery to target
decreasing target density or responsiveness
increasing repair mechanisms
compensation of dysfunction

Toxicology (20 decks)

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