Molecular Cellular Biochem
Chromatin structure
DNA 100pstwicearoundhistone
nucleosome beads on a string
H1 bindsnucleosome t linkerDNA
stabilizes chromatin
phosphateprovides 0 charge
arg lys provide charge
mitosis condensesintochromosomesin Sphas
mitochondria havetheir OWN DNA
circular NOhistones
teterochromatin Highlycondensed transcriptionally inactive
Euchromatin Expressed transcriptionallyactive
DNA Methylation CPG Methylation makes DNA Mute
tistone Methylation HistoneMethylation MakesMostDNA Mute
tistone Acetylation HistoneAcetylation makesDNA Active
tistone deacetylation t acetylgroups tightenedcoiling t transcription
Nucleotides
Nucleotides base nbosephosphate
Nucleosides baseribosesugar
Purines PURE As Gold
AG 2 rings
PYramidines CUTthe PY
CUT I ring
Thyminehas a methyl
RNA Uracil C G bonds are like
DNA Thymine Crazy Glue
methylation
uracil thymine
, DNAReplication semiconservative 5 73 morecomplex in eukaryocytes
Origin ofreplication whereDNA replication begins TATA boxoftenfound in
promotor originregions
Replicationfork Y shapedregionwhereleading laggingstrands are
synthesized
Helicase Halves DNA unwindsDNA replication fork
BLMmutation I Helicase BLOOMsyndrome
SSbindingproteins prevent strands from reannealing
DNA topoisomerases create single double stranded break in helixto
add remove supercoils
Primase creates RNAprimer on DNA so DNApot III
can initiate replication
prokaryotes only elongates leadingstrandbyadding
If
3 longer elongates deoxynucleotides to 3 end
DNA potIngram
I prokaryotes only degrades RNA primer replacesw DNA
DNALigase LinksDNA catalyzesformationofphosphodiesterbonds
joins Okazaki fragments
Telomerase TAGSforGreatness Glory adds TTAGGG to 3 end
oftendysregulated in CANCER
DNA mutations
silent substitutioncodesforSAME aa usu 3rdpos ofcodon
missense substitution codesfor CHANGED aa ex sicklecell Val glutacid
nonsense substitution codesfor earlystop codon stop thenonsense
frameshift del insertionnot divisibleby3 fxmaybealtered
Sachs Muscular dystrophy
splicefifty retained intron in mRNA impairedprotein altered fx
ex Marfan dementia epilepsy cancer
Chromatin structure
DNA 100pstwicearoundhistone
nucleosome beads on a string
H1 bindsnucleosome t linkerDNA
stabilizes chromatin
phosphateprovides 0 charge
arg lys provide charge
mitosis condensesintochromosomesin Sphas
mitochondria havetheir OWN DNA
circular NOhistones
teterochromatin Highlycondensed transcriptionally inactive
Euchromatin Expressed transcriptionallyactive
DNA Methylation CPG Methylation makes DNA Mute
tistone Methylation HistoneMethylation MakesMostDNA Mute
tistone Acetylation HistoneAcetylation makesDNA Active
tistone deacetylation t acetylgroups tightenedcoiling t transcription
Nucleotides
Nucleotides base nbosephosphate
Nucleosides baseribosesugar
Purines PURE As Gold
AG 2 rings
PYramidines CUTthe PY
CUT I ring
Thyminehas a methyl
RNA Uracil C G bonds are like
DNA Thymine Crazy Glue
methylation
uracil thymine
, DNAReplication semiconservative 5 73 morecomplex in eukaryocytes
Origin ofreplication whereDNA replication begins TATA boxoftenfound in
promotor originregions
Replicationfork Y shapedregionwhereleading laggingstrands are
synthesized
Helicase Halves DNA unwindsDNA replication fork
BLMmutation I Helicase BLOOMsyndrome
SSbindingproteins prevent strands from reannealing
DNA topoisomerases create single double stranded break in helixto
add remove supercoils
Primase creates RNAprimer on DNA so DNApot III
can initiate replication
prokaryotes only elongates leadingstrandbyadding
If
3 longer elongates deoxynucleotides to 3 end
DNA potIngram
I prokaryotes only degrades RNA primer replacesw DNA
DNALigase LinksDNA catalyzesformationofphosphodiesterbonds
joins Okazaki fragments
Telomerase TAGSforGreatness Glory adds TTAGGG to 3 end
oftendysregulated in CANCER
DNA mutations
silent substitutioncodesforSAME aa usu 3rdpos ofcodon
missense substitution codesfor CHANGED aa ex sicklecell Val glutacid
nonsense substitution codesfor earlystop codon stop thenonsense
frameshift del insertionnot divisibleby3 fxmaybealtered
Sachs Muscular dystrophy
splicefifty retained intron in mRNA impairedprotein altered fx
ex Marfan dementia epilepsy cancer
