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Flashcards in geneexpression Deck (47)
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1
Q

number of cells required to clone an animal

A

one

2
Q

transcripitionally active chromatin

A

euchromatin

4
Q

region that controls gene transcription

A

regulatory region

5
Q

transcriptionally inactive

A

heterochromatin

6
Q

regulatory regions control genes in this manner

A

turn genes on and off

7
Q

stretches of Dna of defined sequences

A

cis-acting

8
Q

regulatory proteins bind to this part of the helix

A

major groove

9
Q

gene regulatory proteins that recognize cis-acting

A

trans-acting

10
Q

structural motifs on gene regulatory proteins recognize these

A

DNA sequences

11
Q

most common and simplest motif

A

helix-turn-helix

12
Q

subclass of helix-turn-helix

A

homeodomain

13
Q

motif in which two alpha helices are joined together in a short coiled-coil structure

A

leucine zipper

14
Q

describe zinc finger motif proteins

A

alpha helices and beta sheets coordinated by zinc atoms

15
Q

creates homodimes and heterodimers

A

helix-loop-helix motif

16
Q

name two gene switches

A

lac operon and tryptophan synthesizing operon

17
Q

exampe of repressors and activators working together

A

lac operon in E.coli

18
Q

number of gene regulaotry proteins in eukaryotes

A

thousands

19
Q

DNA sequence where the general transcriptioin factors and polymerase aseemble

A

promotor

20
Q

regulatory sites that are distant from the promotor

A

enhancers

21
Q

gene regulaotry proteins consist of two domains

A

structural motif and activation domain

22
Q

repressors work in these 2 ways

A

inactivate transcription factors and change chromatin

23
Q

ways activity of gene regulaaotyr proteins are regulated

A

proteins synthesis, ligand binding, protein phosphorylation, addition of second subunit, unmasking, stimulation of nuclear entry, release of membrane

24
Q

group of proteins that form together on an enhancer to regulate transcription

A

enhanceosome

25
Q

DNA sequeces that prevent regulaotyr proteins form influencing distant genes

A

insulators

26
Q

example fo set of genes coordinated by single protein

A

glucacorticoid receptor

27
Q

clonl inheriatnce fo a condensed inactive X chromosom in female mammals

A

x-inactivation

28
Q

heritable, reversible changes in the genome that regulate gene expressoin

A

epigenetics

29
Q

effect of methylation on some genes

A

allows other proteins to bind nad gene shut down

30
Q

how methylation causes cancer

A

shutting down tumor suppressor genes

31
Q

def of imprinting

A

diff. expression fo a gene allele depending on parental origin

32
Q

splice variants linked to these diseases

A

breast cancer and thalassemias

33
Q

name 3 extracellular signals

A

peptide horomons, growth factors, lipid soluble steroid horomones

34
Q

sufficient cellular iron has this effect on trasnferrin receptor

A

degradation

35
Q

proteins involved in the active transport of mRNA out of nucleus

A

hnRNA binding proteins

37
Q

RNA that silence viral gene expression

A

miRNA, siRNA, lincRNA

38
Q

low cellular iron prevents this

A

mRNA degradation

39
Q

20% of human genes encode these

A

antisense mRNA

40
Q

Fragile X

A

x-linked disorder cause of common form of retardation

41
Q

binds and sequesters intracellular iron

A

ferritin

42
Q

low iron requires cells to do this to ferritin production

A

shut down

43
Q

addition of a carbohydrate

A

glycosylation

44
Q

kinase make protein active or inactive vis this

A

phosphorylation

45
Q

lipid modifications target a protein to this structure

A

membane

46
Q

can unmask a functional unit of a protein

A

cleavage

47
Q

effect of (+) lactose ins lac operon

A

no repressor

48
Q

effect of (+)glucose in lac operon

A

no cap

49
Q

situation where operon is on

A

(-) glucose (+) lactose, cap on, reperessor not bound