Lecture 25: Epigenetics & Environmental Toxins

Question 1

nucleotide (3 parts)

Answer 1

5 carbon sugar + nitrogenous base + phosphate

Question 2

nucleoside (2 parts)

Answer 2

5 carbon sugar + nitrogenous base

Question 3

2 types of 5 carbon sugar

Answer 3

ribose, 2-deoxyribose

Question 4

2 types of nitrogenous base

Answer 4

purine

pyramidine

Question 5

nucleic acid

Answer 5

chain of nucleotides

Question 6

codon

Answer 6

genetic code - sequence of three nucleotides that code for particular amino acid

Question 7

2 purines

Answer 7

adenine

guanine

Question 8

pyrimidines

Answer 8

cytosine
thymine
uracil

Question 9

3 differences between DNA and RNA

Answer 9

1. ribose sugar (deoxy ribonucleic acid vs ribonucleic acid)
2. T & U (thymidine vs uracyl)
3. strand (double vs single)

Question 10

translation of mRNA to protein occurs on ___

Answer 10

ribosomes

Question 11

three types of RNA

Answer 11

mRNA
tRNA
rRNA

Question 12

the epigenome is an essential part of the nexus of ___

Answer 12

nature and nurture

Question 13

3 most studied epigenetic mechanisms

Answer 13

1. DNA methylation
2. mods to histones
3. microRNA regulation of DNA expression

Question 14

DNA methylation

Answer 14

covalent attachment of methyl groups to particular regions of a gene, spec cytosine of a cytosine-guanine dinucleotide

Question 15

effect of DNA methylation

Answer 15

reduce transcription of gene

Question 16

chromatin

Answer 16

complex of small spherical histone proteins around which DNA wraps

Question 17

what loosens chromatin structure?

Answer 17

acetylation, methylation, or phosphorylation of lysine residues of histone tails

Question 18

nucleosome

Answer 18

segment of DNA wrapped around a histone octamer consisting of two copies each of four core histones

Question 19

epigenetic modifications are critical for ___

Answer 19

cell differentiation

Question 20

significant overeating leads to (2)

Answer 20

1. genes for obesity overexpressed

2. genes for longevity underexpressed

Question 21

DNA methylation enzyme

Answer 21

DNA methyltransferases (DNMT1 and DNMT3a)

Question 22

histone acetylation enzyme

Answer 22

histone acetyltransferases (CREB-binding factor protein)

Question 23

histone acetylation can be revesed by ___

Answer 23

histone deacetylases

Question 24

DNA ticketing theory of memory

Answer 24

methyl groups added or removed from DNA could serve a persistent memory function

Question 25

David Sweatt (3 conclusions)

Answer 25

pioneering epigenetic research 1. DNMT activity necessary for experience-driven long-term behavioral change 2. DNA methylation may work with histone mods to regulate memory formation and storage in adult CNS 3. outcomes of epigenetic marks differ according to brain region and stage of memory formation

Question 26

protein that increases in response to drug use

Answer 26

delta FosB

Question 27

three categories of drug effects

Answer 27

1. rapid response and tolerance 2. accumulating and temporary abstinence 3. enduring in abstinence

Question 28

where is delta FosB rapidly induced? (2)

Answer 28

1. nucleus accumbens | 2. dorsal striatum

Question 29

how does delta FoxB regulate gene transcription? (2)

Answer 29

1. DNA methylation | 2. histone mods

Question 30

animals chronically exposed to drugs of abuse show elevated BDNF in ___

Answer 30

VTA

Question 31

persistent organic pollutants (4 rqs)

Answer 31

synthetic organic compounds 1. resistant to degradation 2. low water solubility 3. high lipid solubility 4. high molecular weights

Question 32

where do POPs accumulate?

Answer 32

aquatic food chain in fatty tissue

Question 33

4 important POPs

Answer 33

1. chlordane 2. DDT 3. polychlorinated byphenyls (PCBs) 4. polychlorinated dibenzo-p-dioxins (PCDDs)

Question 34

2 semi persistent organic pollutants

Answer 34

1. bisphenol A (BPA) | 2. polybrominated diphenyl ethers (PBDEs)

Question 35

4 MoA of PCBs

Answer 35

1. endocrine disruption 2. alt in 2nd messenger systems 3. interference in Ca2+ homeostasis 4. inhibition of DA reuptake transporter

Question 36

use of PBDEs

Answer 36

flame retardants in plastics and foam

Question 37

congener of PBDEs still produced in Eu and US

Answer 37

decaBDE

Question 38

where are PBDEs found? (5)

Answer 38

1. air 2. soil 3. house dust 4. food 5. animals

Question 39

use of PBDEs

Answer 39

flame retardants

Question 40

3 effects of PBDEs

Answer 40

1. perturbation of thyroid system 2. alterations in signal transduction pathways 3. alterations in sex hormones

Question 41

BPA use

Answer 41

used in production of plastics

Question 42

2 most frequent locations of PBA

Answer 42

epoxy-lined food cans and water bottles

Question 43

primary MoA of PBA

Answer 43

endocrine disruption

Question 44

chlordane type of pollutant

Answer 44

insecticide

Question 45

chlordane half life

Answer 45

10-20 years

Question 46

2 classes of insecticides

Answer 46

1. organophosphates (OPs) | 2. pyrethrins/pyrethroids

Question 47

two uses of organophosphate

Answer 47

1. insecticide | 2. nerve gas

Question 48

MoA of organophosphates

Answer 48

block AChE resulting in cholinergic syndrome

Question 49

what pesticide promotes epigenetic transgenerational inheritance of adult-onset disease?

Answer 49

methoxychlor

Question 50

methylbromide

Answer 50

insecticide, potent neurotoxin

Question 51

MoA of pyrethrins/pyrethroids (2)

Answer 51

1. disruption of voltage-gated Na+ channels (repetitive firing and increased Na+ influx) 2. bind to and block GABA

Question 52

MoA of lead

Answer 52

interference with calcium metabolism

Question 53

Pb exposure is correlated with __ (3)

Answer 53

1. IQ decline in children 2. reduced grey matter in prefrontal cortex 3. severe encephalopathy

Question 54

MoA of mercury

Answer 54

inhibition of protein synth