Epigenetics -- Lecture 17 Flashcards
epigenetic modifications are….
modifications that change the expression of genes w/o changing the DNA sequence of the gene
epigenetic modifications:
example of epigenetic modification is:
turning a gene on or off
epigenetic modifications:
epigenetic changes often change the ___
chromatin structure of a gene
epigenetic modifications:
___ often change the chromatin structure of a gene
epigenetic changes
chromatin review:
epigenetic modifications change how ___ DNA and ___ bind to each other
how tightly DNA and histones bind to each other
chromatin review:
epigenetic modifications change how tightly ___ and histones ___ to each other
DNA and histones bind to each other
chromatin review:
___ change how tightly DNA and histones bind to each other
epigenetic modifications
chromatin review:
there are ___ types of chromatin (what are the types)
2 types
euchromatin
heterochromatin
types of chromatin:
euchromatin:
DNA and ___ are ___ associated and DNA ___ accessible to ___
DNA and histones are loosely associated and DNA is accessible to transcription factor/RNA Pol binding
types of chromatin:
heterochromatin:
DNA and ___ are ___ associated and DNA and ___ accessible to ___
DNA and histones are tightly associated and DNA is not accessible to transcription factor/RNA Pol binding
types of chromatin:
chromatin remodeling (definition)
changing the chromatin state
histone acetylation:
acetyl groups are ___
negatively charged
histone acetylation:
___ are negatively charged
acetyl groups
histone acetylation:
the amino terminal tails of histone proteins extend out from the ___. They can be ___
nucleosome core
acetylated
histone acetylation:
the ___ of histone proteins extend out from the ___. They can be acetylated.
amino acid terminal tails
nucleosome core
histone acetylation:
the amino terminal tails of ___ extend out from the nucleosome core. They can be acetylated
histone proteins
histone acetylation:
negatively charged ___ are attached to lysine in the N-terminal tails of histones
acetyl groups
histone acetylation:
___ acetyl groups are attached to lysine in the N-terminal tails of histones
negatively charged
histone acetylation:
negatively charged acetyl groups are attached to ___ in the N-terminal tails of histones
lysine
histone acetylation:
negatively charged acetyl groups are attached to lysine in the ___ of histones
N-terminal tails
histone acetylation:
negatively charged acetyl groups are attached to lysine in the N-terminal tails of ___
histones
histone acetylation:
the added ___ charges makes the histones more ___ charged
negative
negatively
histone acetylation:
the added negative charges makes the ___ more negatively charged
histones
HATs and HDACs:
histones are acetylated by ___
histone acetyl transferases (HATs)
HATs and HDACs:
histones are ___ by histone acetyl transferases (HATs)
acetylated
HATs and HDACs:
histones are deacetylated by ___
histone deacetylases (HDACs)
HATs and HDACs:
histones are ___ by histone deacetylases (HDACs)
deacetylated
HATs and HDACs:
high levels of acetylation is ___
histones are more ___ charged
hyperacetylation
negatively
HATs and HDACs:
___ levels of acetylation is hyperacetylation
___ are more negatively charged
high
histones
HATs and HDACs:
relaxed chromatin genes are ___ likely to be expressed
more
HATs and HDACs:
___ genes are more likely to be expressed
relaxed chromatin genes
DNA methylation:
a ___ can be added to ___ in DNA to form 5-methylcytosine
methyl group
cytosines
DNA methylation:
a methyl group can be added to cytosines in ___ to form ___
DNA
5-methylcytosine
DNA methylation:
the methyl group:
a physical barrier to the binding of transcription factors (inhibits gene transcription)
DNA methylation:
cytosines methylated by ___
DNA methyl transferases (DNMTs)
DNA methylation:
___ methylated by DNA methyl transferases (DNMTs)
cytosines
DNA methylation:
cytosines demethylated by ___
DNA demethyases
DNA methylation:
___ demethylated by DNA demethyases
cytosines
DNA methylation:
cytosines ___ by DNA methyl transferases (DNMTs)
methylated
DNA methylation:
cytosines ___ by DNA demethyases
demethylated
DNA methylation:
are all cytosines methylated?
no
not all cytosines are methylated:
only cytosines that are ___ are methylated
followed by a guanine (5’ CG 3’)
not all cytosines are methylated:
many genes in the human genome have ___ called CpG islands (C phosphodiester bonded to a G)
CG-rich regions of DNA sequence
not all cytosines are methylated:
many genes in the human genome have CG-rich regions of DNA sequence called ___
CpG islands (C phosphodiester bonded to a G)
not all cytosines are methylated:
CpG islands often located in the ___
promoter region of genes
epigenetic modifications:
changes in the levels of ___ and ___ combine to remodel chromatin and affect gene transcription
histone acetylation and DNA methylation
epigenetic modifications:
changes in the levels of histone acetylation and DNA methylation combine to ___ and ___
remodel chromatin and affect gene transcription
epigenetic modifications:
euchromatin (modifications)
hyperacetylation of histones
hypomethylation of DNA
promotes gene expression
epigenetic modifications:
heterochromatin (modifications)
hypoacetylation of histones
hypermethylation of DNA
inhibits gene expression
epigenetic modifications fine-tune gene expression:
different ___ have different methylation/acetylation patterns which contribute to differences in gene expression
cell types
epigenetic modifications fine-tune gene expression:
different cell types have different ___ patterns which contribute to differences in gene expression
methylation/acetylation patterns
epigenetic modifications fine-tune gene expression:
different cell types have different methylation/acetylation patterns which contribute to differences in ___
gene expression
epigenetic in development:
in the sperm:
the pattern of epigenetic modifications favor the expression of genes that will ___
promote maximum growth of the fetus
epigenetic in development:
in the egg:
the pattern of epigenetic modifications favor the expression of genes that will ___
modest growth of the fetus
parental conflict theory:
paternal and maternal gene expression patterns ___ each other
oppose
parental conflict theory:
a ___ results in fit offspring that allow the mother to remain healthy and able to reproduce again
balance
parental conflict theory:
an ___ can result in offspring that are either:
too small/weak and unfit to survive
grow so large that it ends up hurting or killing the mother or leaves her unable to reproduce again
