C8 Control of Gene Expression Flashcards Preview

Biol 3310 > C8 Control of Gene Expression > Flashcards

Flashcards in C8 Control of Gene Expression Deck (28):
1

Most important level of gene control

transcription

2

? bind to DNA to switch genes on and off

gene regulatory proteins

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Many Gene regulatory proteins use ? to make specific contact with DNA

motifs

4

related genes close together in bacteria

operons

5

CAP is active when cAMP levels are high and acts to ? transcription

promote

6

The lactose operon is transcribed when ? is present and ? is absent

lactose is present and glucose is absent

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RNAP I makes

rRNA

8

RNAP II makes

mRNA and snRNA

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RNAP III makes

tRNA

10

Bacterial RNAPs use ? to recognize promoters

sigma factors

11

Eukaryotic RNAPs use ? to recognize promoters

General Transcripton factors

12

Some transcription factors are ? that reduce the positive charge on histones within the nucleosomes and loosen their grip on DNA

histone acetylases

13

riboswitch

RNA that can control its own transcription by inducing a conformation change

14

Binds to the trp operator to control tryptophan gene transcription

trp repressor

15

Helps RNAP bind to weak promoter sequences

CAP activator

16

substrate that turns on CAP activator

cAMP

17

Expression of ?, a transcription factor, in a skin cell converts the cell to a muscle cell

myoD

18

Ways gene expression can be transmitted to daughter cells

positive feedback loop, DNA methylation, condensed chromatin structure

19

positive feedback loop

key transcription regulator activates transcription of its own gene

20

DNA methlation has this generally turns off genes by...

attracting proteins that block expression

21

Regulation of translation initiation (4)

Riboswitch, repressor/activator, thermosensor, antisense RNA

22

micro RNAs (miRNAs) control at least ? of all protein coding genes

1/3

23

Humans produce more than ? different miRNAs

400

24

miRNA function

Assemble with proteins to form RISC which patrols cytoplasm looking for complementary RNA sequences to destroy

25

RISC stands for

RNA induced silencing complex

26

Describe RNA interference

double stranded RNA is introduced. broken down into fragments by DICER nuclease. Fragments called siRNAs. siRNAs combine with proteins to form RISCs

27

many activators summon ? which attaches an acetyl groups to histones

histone acetylases

28

combinatorial control

eukaryotic genes are controlled by combinations of regulatory proteins