Gene regulation

Question 1

how do bacteria regulate their genes?

Answer 1

in respnse to the environment and conditions

Question 2

what is gene regulation

Answer 2

process of changing and controlling which genes in a cells DNA are expressed to make functional products such as proteins

Question 3

what does the set of genes being expressed determine?

Answer 3

the cells unique properties

the enes control the set of proteins and this RNAS

Question 4

why do we alter gene expression?

Answer 4

variation
supression of junk
controls which genes are turned on or not
differeent patterns of speaclist cells

Question 5

what is a transciptional factor

Answer 5

binds to DNA and switches on or off gnes in repression or in activation
they can bind to other factors leading to pathways
also involved in autoregulation/self regulation

Question 6

what is a T shape line?

Answer 6

factor that shuts down or repressed the genome

Question 7

what does an arrow repressent in a flow diagram of transciptional factors

Answer 7

activated or increased genome expression

Question 8

what inside factors affect gene regulation

Answer 8

proteins, damage to DNA, amount of ATP

Question 9

whatoutside factors affect gene regulatin

Answer 9

chemical signals from other cells, mechanical signals from ECM, nutrient levels

Question 10

how is information converetd to a change in gene expression?

Answer 10

molecular pathways

Question 11

describe the process of a growth signal leading to the cell growing and dividing

Answer 11

1. cell detects the factor through physical binding of the factor to receptor protein of cell surface
2. binding causes receptor to change shape leading to triggering of chemical events activating transciptional factors
3. TF’s bind to sequences of DNA in nucleus and cause transcription of certain genes

Question 12

for the growth signalling pathway, what is the products/effect at the end

Answer 12

various types of proteins that make the cell dividie and push the cell cycle on

Question 13

what factors of eukaryotic gene expression can be controlled?

Answer 13

chromatin acessability
transciption
RNA processing

Question 14

how can chromatin accessability be controlled?

Answer 14

more open or relaxed makes the genes more available for transciption
location of gene promotors relative to nucleosomes and to where the DNA attaches to chromoosomes can affect whether its transcribed

Question 15

what can you do to chromatin to affect gene expression

Answer 15

chemical modification to histones and chromatin affects structure and gene expression

Question 16

how can trancription be altered?

Answer 16

sets of transcriptional factors proteins can bind to speicific DNA sequences in or near a gene to promote or repress its transcitpion into RNA

Question 17

how can RNA processing be alterered to affect gene expression

Answer 17

splicing, addition of poly-A tail to RNA can be regulated so it can exit the nucleus
different mRNAs may be made from the same pre-mRNA by alternative splicing

Question 18

how does the stability of the RNA molecule impact gene expression?

Answer 18

lifetime of mRNA molecule in cytosol affects how many prpteins can be made from it

Question 19

what do regulators do?

Answer 19

inrease or inhibitr translation of mRNA

Question 20

what can a small regulator RNA do?

Answer 20

block transmittion of target mRNA or chop it up

Question 21

what can be done to proteins to affect activity?

Answer 21

chopped up, tagged with chemical groups

affects the activity and behaviour of the proteins

Question 22

what is DNA methylation

Answer 22

some genes can be methylated to affect their function

Question 23

what causes DNA methylation

Answer 23

some enzymes methylate it

Question 24

what does methylation cause?

Answer 24

if heavy methylated, genes more likely to be turned off and not expressed
removal of methyl groups can turn the genes on

Question 25

why is methylation important

Answer 25

used in the long-term inactivation of genes that occurs during cells differentiation in embryo differentaition

Question 26

what can improper DNA methylation cause?

Answer 26

deficient DNA methylation due to lack of proper enzymes can lead to abnormalities in embryos

Question 27

key features of prokaryote gene regulation

Answer 27

very simple
regulation has little steps
no introns, only one piece

Question 28

what regulates prokaryote gene regulation?

Answer 28

operons turn genes on

no distinct nucleus to expression in cytoplasm

Question 29

how do bacteria use gene regulation?

Answer 29

they conserve energy and resources to have a selective advantage over those that cant
natura selection favours bacteria that can express only the genes where the products are needed

Question 30

how have ecoli adapted gene regulation?

Answer 30

they live in the errati conditions of the stomach and depend on nutrients from the environment
if its lacking amino acid tryptophan, they can respond by activating metabolic pathway to make it from another compound. if the host then eats meal with tryptophan, the bacteria stop making it

Question 31

why have ecoli adapted for gene regulation in stomach conditions?

Answer 31

stops the bacteria wasting material

they change their metabolism to suit environments

Question 32

what is a CIS acting sequnce?

Answer 32

one that binds to proteins that in turn assisi the binding of RNA

Question 33

what is a TRANS acting regulator protein?

Answer 33

they work through sequence-specific DNA binding to their CIS acting regulatory agent sequences

Question 34

whatis a cis regulatory regions/

Answer 34

bit of DNA where the repressor or factor binds