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1

inducible operon

cluster of genes that is turned off unless needed. turned on by an inducer

1

repressible operon

cluster of genes that is on unless not needed. turned off by co-repressor activating an inactive repressor

2

short stretch of DNA between the promoter and genes that controls transcription of genes. in operons. activators and repressors bind here to increase or decrease gene expression & transcription

operator

3

the study of nucleic acids and proteins, often focuses on gene expression

molecular biology

3

genes that are actively expressed all of the time, needed for cell function

constitutive genes

3

a cluster of genes with one promoter. these genes follow this. all genes in this cluster get transcribed together (all or nothing)

operon

3

enhancers

in eukaryotes, sequences that bind to activator proteins and loops back to promoter to make initiation complex so genes can be transcribed. it is located upstream (before) the promoter

3

late stage of lytic cycle

encodes viral capsid (coat on outside of enzyme) proteins and enzymes to lyse the host cell (make it explode) and release viral particles

3

use gene regulation and transcription to take over host cell. "a piece of bad news wrapped in protein"

viruses

3

alternative splicing

this creates different mRNAs from the same gene. splices different exons together and results in new proteins. 1 gene can make multiple proteins. don't need 1 gene for every single protein

4

proteins that interfere with RNA polymerase. mechanism to try to stop an infection from a virus

transcription terminator

5

translational repressor

binds to mRNA to prevent mRNA from attaching to ribosome.

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common promoter sequence, a recognition sequence. how polymerase recognizes it is in the spot to start transcription

TATA box

7

regulatory proteins

proteins that control whether a gene is active. activator or repressor binds to a operator in prokaryotes. in eukaryotes, they bind to an enhancer or silencer

8

viral reproductive cycle. 2 stages: early and late

lytic cycle

9

molecular biology

the study of nucleic acids and proteins, often focuses on gene expression

9

lytic cycle

viral reproductive cycle. 2 stages: early and late

10

binds to mRNA to prevent mRNA from attaching to ribosome.

translational repressor

11

diffuse and light staining chromatin containing DNA for mRNA transcription

euchromatin

13

in some cells, one X chromosome (from mom) is inactivated and in other cells the other X chromosome (from dad) is inactivated. in females, patchy

mosaic

14

epigenetics

changes to DNA and chromatin that regulate (inactivate) large regions of genes (even a whole chromosome). regulating gene transcription on a large scale. reversibly altering large portions of DNA and chromatin. reversible and can be passed on to daughter cells. affected by environmental factors. e.g. DNA methylation

15

co-repressor

binds to an inactive repressor and activates it so repressor binds to operator which blocks transcription. tryptophan does this. turns off repressible operon

15

in females, one X is inactivated (this is a kind of heterochromatin). this is a mosaic

Barr Body

15

at 5' end of mRNA to prevent its breakdown. this can be modified (marked to be translated). if it is not modified, mRNA is not translated

5' cap

16

TATA box

common promoter sequence, a recognition sequence. how polymerase recognizes it is in the spot to start transcription

16

DNA wrapped around histone

nucleosome

17

operon

a cluster of genes with one promoter. these genes follow this. all genes in this cluster get transcribed together (all or nothing)

19

binds to an inactive repressor and activates it so repressor binds to operator which blocks transcription. tryptophan does this. turns off repressible operon

co-repressor

20

DNA methylation

when C's in promoter are methylated, a methyl group is  covalently added to it. methyl groups block RNA polymerase so that gene can't turn on. these methylated genes are inactivated and turns off. type of epigenetic change. these can be inherited and reversed (so they can be adtivated again)

22

sigma factors

proteins that bind to RNA polymerase and direct RNA polymerase to specific promoters. allows us to turn on related genes all around the cell together at the same time. only in prokaryotes