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Flashcards in Chapter Eight Deck (44):
1

compare neuron and liver cell

same genome but express different RNAs and proteins for different tasks

2

extra embryonic membranes

connections w mother, maternal determinant

3

transcription control

prevents unnecessary intermediates; DNA to RNA transcript never happens

4

transcription regulator

interacts w major groove of DNA double helix; bind via homeodomain or lucine zipper

5

transcription factors

activate/inhibit transcription of genes by altering accessibility of RNA polymerase to gene promoter; bind DNA in major groove of DNA helix; bind edges of bases w/o disrupting H bonds that hold bases together

6

arginine residues

makes contact w ATTA in minor groove and dictate where/in which groove each TF will act

7

homeodomain

3 alpha helices makes many contacts w DNA at particular seq; contact adenine via asparagine

8

leucine zipper

2 alpha helices (coiled coil) makes many contacts w DNA that can span both major and minor groove (e.g. c-myc) occur ever 7 AAs

9

operon

cluster of bacterial genes transcribed from single promoter

10

operon in mammels

each gene regulated individually and 1 gene per mRNA

11

tryptophan genes

for synthesis transcribed w/i single mRNA mol

12

repressor proteins

bac genes can be switched on/off w repressor proteins (e.g. tryptophan syn regulated by repressor)

13

activator protein (TF)

inc efficiency of transcription; bind regulatory seq (enhancer) on DNA to enhance RNA polymerase action + reg transcription

14

active metabolite

binding of active metabolite or small mol in abundance controls repressor + activator proteins

15

lac operon

expressed when (-) glucose and (+) lactose; lac repressor inactive and CAP induced; in E colic encodes proteins req to import/ingest lactose when glucose (preferred C source) is absent

16

gene activation

via activator protein, DNA as tether, repressor proteins

17

DNA as tether in gene activation

facilitating TF bound to enhancer (even for apart) to interact w mediator protein, general TFs and RNA polymerase to induce transcription

18

repressor proteins in gene activation

inhibit assembly of polymerase complex at promoter + connection w enhancer

19

chromatin modifying proteins

help eukaryotic transcriptional activators initiate gene transcription

20

actetylation

relaxes chromatin/promoter is more accessible accompanied by demethylation and TATA box is more accessible

21

specific transcription factors

bind directly to DNNA regulatory sequences (repressors and activators)

22

general transcription factors

bind to RNA polymerase and facilitate polymerase action in same way for all genes and must be present for transcription to proceed

23

combination control

eu gene seq. use specific transcriptions factors w some acting as repressors and some as activators

24

one reg. protein

controls expression of many genes (e.g. glucose control)

25

bacterial transcription

one polymerase type, no general trans. factors, genes close together w short pieces of non transcribed DNA in between

26

eukaryotic transcription

RNA polymerase I, II, III; TFs are needs before RNA polymerase can begin transcription; DNA in nucleosomes and more compact forms of chromatin influence trans. initiation

27

gene proximity in eukaryotes

separated by as many as 100K nucleotide pairs; reg. proteins influence trans initiation even at distance; more complex trans. reg

28

differentiated cell type to another

small number of transcription reg can do this (e.g. liver cell to neuronal cell)

29

reprogramming differentiated cells

fibroblasts reprogrammed using defined TFs (e.g. kit) to get pluripotent stem cells able to develop into any cell in the body (3 main germ lines) but not extra embryonic

30

cell types during development

combos of few genes reg proteins generate many diff cell types

31

master regulatory protein

activates trans of own genes and cell specific genes (feedback loop)

32

TF Myo D

converts fibros to myoblasts; TF can also cause cellular reprogramming; Myo D can change cells from other non mesoderm germ layers (e.g. neural and liver cells)

33

DNA methylation

patterns are inherited when cell divides

34

maintenance methyltransferase

immediately after DNA rep recognizes specific GC paired w methylated GC

35

epigenetic inheritance

histone modifications inherited by daughter chromosomes w/o altering DNA nucleotide seq.; enzyme bind to parents histones and est. pattern of chromosome structure found in parent

36

riboswitches

mechanisms for controlling gene expression usually involve regulatory protein; some mRNA seq. can regulate their own transcription + translation

37

self regulating mRNAs

have short sequences of RNA that change conformation when bound to RNA and regulate gene expression

38

bacterial gene expression control

regulating translation of mRNA; seq specific RNA binding proteins inhibit binding of ribosome to customary start point self controlling mech to prevent excess protein production

39

listeria monocytogenes w thermosensor

bacterium arrives in host higher temp allows translation of virulent genes important in pathogens

40

eukaryotic miRNAS

tiny RNAs that seek out + destroy mRNAs w complementary bases to control gene expression

41

siRNAs

produces from DS foreign RNAs in process of RNA interference

42

RNA polymerase I

transcribes most rRNA genes

43

RNA polymerase II

transcribes all protein coding genes + some genes for small RNAs (e.g. those in spliceosomes)

44

RNA polymerase III

transcribes tRNA genes, 5S rRNA gene, genes for small structural RNAs