Epigenetics and disease
increased methylation hypermethylation of tumour suppressor genes
or reduced methylation hypomethylation of protooncogenes causes
uncontrolled cell division
drugs that reduce DNAmethylation used in chemotherapy for cancers
caused by hypermethylation of tumoursuppressorgene
drugswhich inhibitenzymes that remove acetyl groupsfromhistones also used
to treat some typesof cancer prevents deacetylation and allow genes to
remain switched on
problem hard to targetdrugs tospecific cancer cells whilst leavingother
cells alone
RNAinterference
small strands of RNA bind to mRNA to form double stranded structure
prevents mRNA from being translated into proteinsandprevents genes
frombeingexpressed
small interferingRNA siRNA
an enzyme cuts large double stranded molecules of RNA into smaller
sections called siRNA
one of 2 SiRNAcombines with an enzyme
siRNAguidesenzyme to a mRNAbypairingup its bases with complementary
ones on a sectionof mRNAmolecule
once in positionenzyme cuts mRNA into smaller sections
mRNA no longercapable of beingtranslated into a polypeptide s gene
has not beenexpressed
cancer bmRNAfragmentsmovedinto a processing
DNA altered bymutation
ismitationnitiangensebinationeronise tn canceaatoformation
of a tumour
tumour abnormal mass of cells whichdevelops into a cancer when they
invadeanddestroysurroundingtissue
Mitntignisnupptressitgenne's stop'inioniiomedrielldivision coding
by for
proteinswhichinhibit mitosis or trigger apoptosis mutation which inactivates
tumour suppressorgenes results in uncontrolled celldivision as proteinnot mad
proto oncogenes stimulate cell divisions by coding for proteins which
triggermitosis mutation which activates proto oncogenes result in formation
of tumour due to uncontrolled cell division
tumours can be benign or malignant
Benign tumour
atesssnoitcaitsteiannteinated cells
doesnot invadeother tissues causingdamage
pieceswhich break off do not start new tumours elsewhere in body
grow slowly
may becomemalignant tumours
less likely to be life threatening
usually removed by surgery alone
rarely reoccur after treatment
, Malignant tumour
mass of undifferentiated cells
is cancerous
uncontrolled cell division
metastasis cells break off and form new tumours
spreadto other parts of body
grow quickly
more likely to be life threatening
removal usually involves radiotherapy and orchemotherapy andsurgery
more frequently reoccur after treatment
Bothtypes of tumours
maydamage organconcerned
may cause blockages
maydamage exert pressure on other organs
Genome
all of the genes present in an organism
Proteome
all of the proteins that can becoded for by genes in organism
DNAsequencing
determining compleDNA base sequence of an organism
onlyaccurate for short sections of DNA s DNAneeds tobe made intoshorte
fragments
determining genome is easier for simpler organismssuch as bacteria
which have less non codingDNAwhereas morecomplicatedorganisms like
humans have more non codingDNA leg introns promoters
determining amino acidsequence and structure of protein itcodesfor is
useful in medical research
Methods of makingDNA fragments
restrictionenzymes scut double stranded DNA at specific recognition sites
recognition sites are palindromic read the same backwards and
forwards
restriction enzyme detects its recognitionsequence and cuts DNAin one
of two ways straight down the middle creating blunt ends or in a
zig zag fashion creating sticky ends
cut doublestranded DNA by hydrolysing phosphodiester backbone
is
increased methylation hypermethylation of tumour suppressor genes
or reduced methylation hypomethylation of protooncogenes causes
uncontrolled cell division
drugs that reduce DNAmethylation used in chemotherapy for cancers
caused by hypermethylation of tumoursuppressorgene
drugswhich inhibitenzymes that remove acetyl groupsfromhistones also used
to treat some typesof cancer prevents deacetylation and allow genes to
remain switched on
problem hard to targetdrugs tospecific cancer cells whilst leavingother
cells alone
RNAinterference
small strands of RNA bind to mRNA to form double stranded structure
prevents mRNA from being translated into proteinsandprevents genes
frombeingexpressed
small interferingRNA siRNA
an enzyme cuts large double stranded molecules of RNA into smaller
sections called siRNA
one of 2 SiRNAcombines with an enzyme
siRNAguidesenzyme to a mRNAbypairingup its bases with complementary
ones on a sectionof mRNAmolecule
once in positionenzyme cuts mRNA into smaller sections
mRNA no longercapable of beingtranslated into a polypeptide s gene
has not beenexpressed
cancer bmRNAfragmentsmovedinto a processing
DNA altered bymutation
ismitationnitiangensebinationeronise tn canceaatoformation
of a tumour
tumour abnormal mass of cells whichdevelops into a cancer when they
invadeanddestroysurroundingtissue
Mitntignisnupptressitgenne's stop'inioniiomedrielldivision coding
by for
proteinswhichinhibit mitosis or trigger apoptosis mutation which inactivates
tumour suppressorgenes results in uncontrolled celldivision as proteinnot mad
proto oncogenes stimulate cell divisions by coding for proteins which
triggermitosis mutation which activates proto oncogenes result in formation
of tumour due to uncontrolled cell division
tumours can be benign or malignant
Benign tumour
atesssnoitcaitsteiannteinated cells
doesnot invadeother tissues causingdamage
pieceswhich break off do not start new tumours elsewhere in body
grow slowly
may becomemalignant tumours
less likely to be life threatening
usually removed by surgery alone
rarely reoccur after treatment
, Malignant tumour
mass of undifferentiated cells
is cancerous
uncontrolled cell division
metastasis cells break off and form new tumours
spreadto other parts of body
grow quickly
more likely to be life threatening
removal usually involves radiotherapy and orchemotherapy andsurgery
more frequently reoccur after treatment
Bothtypes of tumours
maydamage organconcerned
may cause blockages
maydamage exert pressure on other organs
Genome
all of the genes present in an organism
Proteome
all of the proteins that can becoded for by genes in organism
DNAsequencing
determining compleDNA base sequence of an organism
onlyaccurate for short sections of DNA s DNAneeds tobe made intoshorte
fragments
determining genome is easier for simpler organismssuch as bacteria
which have less non codingDNAwhereas morecomplicatedorganisms like
humans have more non codingDNA leg introns promoters
determining amino acidsequence and structure of protein itcodesfor is
useful in medical research
Methods of makingDNA fragments
restrictionenzymes scut double stranded DNA at specific recognition sites
recognition sites are palindromic read the same backwards and
forwards
restriction enzyme detects its recognitionsequence and cuts DNAin one
of two ways straight down the middle creating blunt ends or in a
zig zag fashion creating sticky ends
cut doublestranded DNA by hydrolysing phosphodiester backbone
is
